Conversion method of resolver coded signal and terminal

Abstract

The invention discloses a resolver coded signal conversion method and a terminal. The method comprises the following steps: acquiring an analog signal transmitted by a resolver encoder; the analog signal is decoded, and position information or speed information of the motor is obtained through calculation; simulating a data protocol of an absolute value encoder, and converting digits of the position information or the speed information; and transmitting the converted position information or speed information to a servo driver. According to the method and the device, the analog signal of the rotary transformer encoder is acquired, decoded and converted into the data format which can be identified by the servo driver, so that the compatibility among different encoder types is realized, the existing servo driver can support the rotary transformer encoder without replacing, the hardware replacement cost is greatly reduced, and the system flexibility is improved.

Description

Technical Field

[0001] The present invention relates to the field of automation, and in particular to a conversion method and a terminal for a resolver coded signal. Background Art

[0002] Servo control systems are widely used in industrial automation, robot control, and precision machining. The core component of servo drives is usually to obtain the position and speed information of the motor through encoders to achieve high-precision motion control. However, most servo drives on the market currently only support specific types of encoders (such as absolute encoders or incremental encoders) and are not directly compatible with resolver encoders.

[0003] The resolver encoder is a sensor with high durability, strong anti-interference ability, and adaptability to harsh environments. It can provide position information and speed information of the motor operation. Due to its simple structure and high reliability, it is widely used in high-demand industrial scenarios. However, the resolver encoder outputs an analog signal (SIN / COS signal), which needs to be converted into a digital signal through a professional decoding circuit and algorithm. Most existing servo drives rely on the position information output by the digital absolute encoder and cannot directly process the analog signal of the resolver encoder. This difference makes it impossible for existing servo drives to adapt to resolver encoders when replaced or upgraded. Users need to replace the drive to support different types of encoders, which increases the cost of hardware replacement and reduces the flexibility of the system.

[0004] At the same time, traditional encoder compatibility solutions usually require redevelopment of the drive model or changes to the drive's internal hardware structure, which not only increases the development cycle and cost, but may also involve the redesign and production of the casing mold, further limiting the promotion and flexibility of the servo system in actual application scenarios. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and a terminal for converting a resolver encoding signal, so as to solve the problem that an absolute value driver cannot be adapted to a resolver encoder.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for converting a resolver coded signal comprises the steps of: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal, and calculating the position information or speed information of the motor; S3, simulating the data protocol of the absolute encoder to convert the number of bits of the position information or speed information; S4, transmitting the converted position information or speed information to the servo driver.

[0007] In order to solve the above technical problems, another technical solution adopted by the present invention is: A conversion terminal for a resolver coded signal comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor completes the following steps when executing the computer program: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal, and calculating the position information or speed information of the motor; S3, simulating the data protocol of the absolute encoder to convert the number of bits of the position information or speed information; S4, transmitting the converted position information or speed information to the servo driver.

[0008] The beneficial effects of the present invention are: providing a method and terminal for converting a resolver encoding signal, which achieves compatibility between different encoder types by acquiring the analog signal of the resolver encoder, decoding and converting it into a data format recognizable by a servo drive, so that the existing servo drive can support the resolver encoder without replacement, greatly reducing the hardware replacement cost and improving the system flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 1 is a flow chart of a method for converting a resolver coded signal in an embodiment of the present invention; Figure 2 Schematic diagram of the architecture of a conversion terminal for a resolver coded signal in an embodiment of the present invention; Figure 3 Schematic diagram of the framework of the MCU in the embodiment of the present invention; Figure 4 is a schematic diagram of the structure of a data frame in an embodiment of the present invention; Figure 5 It is a flow chart of the execution of the absolute value communication protocol state machine in an embodiment of the present invention; Figure 6 1 is an overview diagram of the architecture of a conversion terminal for a resolver coded signal in an embodiment of the present invention; Figure 7 Detailed architecture diagram of a conversion terminal for a resolver coded signal in an embodiment of the present invention; Description of labels: 1. A conversion terminal for a resolver coded signal; 2. A memory; 3. A processor. DETAILED DESCRIPTION

[0010] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0011] Please refer to Figure 1 as well as Figure 2 , a method for converting a resolver coded signal, comprising the steps of: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal, and calculating the position information or speed information of the motor; S3, simulating the data protocol of the absolute encoder to convert the number of bits of the position information or speed information; S4, transmitting the converted position information or speed information to the servo driver.

[0012] From the above description, it can be seen that the beneficial effect of the present invention is that by acquiring the analog signal of the resolver encoder, decoding and converting it into a data format recognizable by the servo drive, compatibility between different encoder types is achieved, so that the existing servo drive can support the resolver encoder without replacement, greatly reducing the hardware replacement cost and improving the system flexibility.

[0013] Specifically, the terminal is equipped with an RDC module (resolver digital converter) and an MCU (microcontroller unit). The SIN / COS analog signal output by the resolver encoder is collected through the resolver RDC module. After receiving the signal, the MCU decodes it, calculates the position information or speed information of the motor, and converts it into a digital signal that meets the communication requirements of the servo drive according to the data protocol of the absolute encoder, and sends it to the servo drive through the 485 interface.

[0014] In an embodiment of the present invention, step S3 specifically includes the following steps: According to the data protocol, the data format of the position information or speed information is converted into a data format readable by the absolute encoder, and control words and CRC check fields are added before and after the data to form a data frame to meet the requirements of the absolute encoder data protocol.

[0015] In some optional embodiments, the 16-bit data format of the position information or speed information is converted into a 24-bit data format according to the data protocol. By converting the 16-bit position information or speed information into a 24-bit data format and adding a control word and a CRC check field based on the 16-bit position information or speed information, the integrity of the data is guaranteed and the requirements of the absolute encoder data protocol are met, thereby improving the reliability and compatibility of the servo drive communication. Specifically, after receiving the 16-bit position information decoded by the resolver RDC, the MCU expands it to 24 bits according to the absolute encoder data protocol, and adds a control word (such as 0x02 for indicating the communication instruction type) and a CRC check field. After forming a complete data frame, it is transmitted to the servo drive through the 485 interface. The above 16 is the conversion of the data format to the 24-bit data format, which is only an example of the data protocol in the present invention, and therefore cannot be understood as a limitation on the present application.

[0016] Please refer to Figure 4 In an embodiment of the present invention, the data frame includes: The control field is used to indicate the type of communication instruction; The status field is used to indicate the running status of the conversion process; A data field is used to store the position information or speed information of the motor; CRC check field: used to check the integrity of the data frame.

[0017] From the above description, it can be seen that by clarifying the data frame structure (including the control field, status field, data field and CRC check field), the efficiency and reliability of data transmission between the servo drive and the resolver expansion module are achieved, which makes it convenient for the servo drive to understand the operating status of the expansion module in real time and receive accurate position information or speed information.

[0018] In some possible implementations, the data field includes eight bytes, and the number of bytes used to store the position information or speed information of the motor is determined according to the received control word, for example, three bytes are used to store the position information or speed information of the motor; on this basis, the data field includes eight bytes, and only three bytes are used to store the position information or speed information of the motor, for example, the data field includes eight bytes DF0-DF7, and only DF0-DF3 (3 bytes) are used to transmit the position information or speed information, while DF4-DF7 are not used. The purpose is to: only transmit necessary data, reduce redundancy, and reduce the burden of data transmission; and, the data packets are smaller, the transmission speed is faster, and it is more suitable for real-time control occasions.

[0019] In an embodiment of the present invention, step S2 specifically includes the steps of: The SIN / COS signal in the analog signal is converted into a digital signal, and the position information or speed information of the motor is obtained by calculation according to the sine-cosine algorithm.

[0020] From the above description, it can be seen that by converting the SIN / COS signal output by the resolver encoder into an analog-to-digital converter and using the sine-cosine algorithm to calculate the position information or speed information of the motor, the data conversion is ensured to be accurate and real-time, meeting the requirements of high-precision servo control. Specifically, after the resolver RDC module receives the SIN / COS signal of the encoder, it converts the analog signal into a digital signal through the ADC module. At the same time, the RDC module uses the sine-cosine algorithm to calculate the amplitude and phase of the sine-cosine signal to obtain the current position information or speed information of the motor, and then sends the position or speed information to the MCU through SPI communication.

[0021] In an embodiment of the present invention, the step S1 further includes step S0: The servo driver is controlled to read the unique identification code of the motor, and the corresponding motor parameter control table is retrieved according to the unique identification code and the operation mode and parameter setting of the motor are matched.

[0022] From the above description, it can be seen that by reading the unique identification code (Motor Code) of the motor before obtaining the resolver encoding signal, the automatic matching function of the servo drive is realized, ensuring the automatic loading of the operating parameters of each motor, reducing manual intervention, and improving the operating efficiency and adaptability of the system. Specifically, after the servo drive is powered on, the Motor Code stored in the resolver expansion module is read by sending a control word (such as 0xEA). The Motor Code contains the type and parameter table information of the motor. The servo drive automatically calls the corresponding parameter table (such as the number of pole pairs, maximum speed, etc.) according to the read Motor Code to complete the initialization configuration.

[0023] A conversion terminal for a resolver coded signal comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the conversion steps of the resolver coded signal are completed.

[0024] The present invention provides a method and terminal for converting a resolver encoding signal, which mainly converts a resolver encoder into an absolute encoder communication format, and can directly adapt to an existing absolute value type driver without changing the driver model. The following is a specific description in conjunction with an embodiment: Please refer to Figure 1 to Figure 2 , Embodiment 1 of the present invention is: A method for converting a resolver coded signal comprises the steps of: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal and calculating the position information or speed information of the motor; S3, simulate the data protocol of the absolute encoder and convert the number of bits of position information or speed information; S4. Transmit the converted position information or speed information to the servo driver.

[0025] That is, in this embodiment, by acquiring the analog signal of the resolver encoder, decoding and converting it into a data format recognizable by the servo drive, compatibility between different encoder types is achieved, so that the existing servo drive can support the resolver encoder without replacement, greatly reducing the hardware replacement cost and improving the system flexibility.

[0026] Preferably, a conversion terminal of a resolver encoding signal includes an RDC module (resolver digital converter) and an MCU (microcontroller unit); wherein the RDC module provides an excitation signal for the resolver encoder and parses the encoder feedback signal SIN / COS to obtain position or speed information, and then sends the position or speed information to the MCU via SPI communication. The RDC module mainly includes: a resolver RDC chip, a power reset clock circuit, an excitation amplifier circuit, an excitation boost power supply, a SIN / COS receiving circuit, etc.

[0027] The main functions of MCU are: simulating the absolute encoder communication data format to communicate with the servo driver, mainly including motor code reading and writing, initializing and configuring the RDC chip, reading position or speed information and converting the information into an absolute value communication protocol and sending it to the servo driver through the serial port, and extending the module operation and fault status judgment and indication.

[0028] Specifically, refer to Figure 3 , MCU includes the functions of serial port receiving interrupt, data timing interrupt and receiving timeout timing interrupt.

[0029] Embodiment 2 of the present invention is: Based on the first embodiment, step S2 specifically includes the following steps: The SIN / COS signal in the analog signal is converted into digital form, and the position information or speed information of the motor is calculated according to the sine-cosine algorithm. At the same time, the SIN / COS signal output by the resolver encoder is converted into digital form, and the sine-cosine algorithm is used to calculate the position information or speed information of the motor to ensure that the data conversion is accurate and real-time to meet the requirements of high-precision servo control. Specifically, after the resolver RDC module receives the SIN / COS signal of the encoder, it converts the analog signal into a digital signal through the ADC module. The RDC module uses the sine-cosine algorithm to calculate the amplitude and phase of the sine-cosine signal to obtain the current position information or speed information of the motor, and then sends the position or speed information to the MCU through SPI communication.

[0030] Step S3 specifically includes the following steps: The 16-bit data format of the position information or speed information is converted into a 24-bit data format, and control words and CRC check fields are added before and after the data to form a data frame to meet the requirements of the absolute encoder data protocol. In the terminal, after receiving the 16-bit position information decoded by the resolver RDC, the MCU expands it to 24 bits according to the absolute encoder data protocol, and adds control words (such as 0x02 to indicate the communication instruction type) and CRC check fields to form a complete data frame, which is then transmitted to the servo drive through the 485 interface.

[0031] Among them, MCU reads the position or speed information of the resolver encoder once every 80uS through SPI communication, and 485 communication reads the position or speed information after MCU conversion once every 100uS. The position or speed information read by 485 is the most recently updated information of SPI. The SPI communication cycle is shorter than that of 485, ensuring that the information read by 485 each time is updated.

[0032] For details, please refer to Figure 4 , the data frame includes: The control field is used to indicate the type of communication instruction; The status field is used to indicate the running status of the conversion process; The data field is used to store the position information or speed information of the motor; the data field includes eight bytes, of which three bytes are used to store the position information or speed information of the motor; CRC check field: used to check the integrity of the data frame.

[0033] The data field includes eight bytes, and only three bytes are used to store the position information or speed information of the motor. For example, the data field includes eight bytes DF0-DF7, and only DF0-DF3 (3 bytes) are used to transmit the position information or speed information, while DF4-DF7 are not used. The purpose is to: only transmit necessary data, reduce redundancy, and reduce the burden of data transmission; and, the data packet is smaller, the transmission speed is faster, and it is more suitable for real-time control occasions.

[0034] In addition, the status field is used to reflect whether there is an abnormality in the conversion process; specifically, a red and green indicator light is set externally, and the specific application is as follows: RDC module operation green indicator light: long light means the module is in good condition and communication with the servo drive is interrupted; flashing means there is no fault and communication with the servo drive is normal.

[0035] RDC module fault red indicator: long off means the module is in the expansion module fault-free state, flashing means the expansion module is in fault state. The fault state includes the communication state between RDC and MCU, and the RDC chip fault information processed by MCU.

[0036] Please refer to Figure 5 The present invention also provides an absolute value communication protocol state machine, which is applied to receive data transmitted by MCU, and specifically includes the following: Set CMD_STATE to represent the communication state machine, which includes three states: CMD_STATE_RDY represents the idle state; CMD_STATE_WREE represents the write EEPROM state; CMD_STATE_RDEE represents the read EEPROM status; (1) When CMD_STATE = CMD_STATE_RDY, enter the idle state branch and judge the received control word: When the control word = 0x02, determine whether it is in a fault state. In a fault state, no response (no data returned); in a non-fault state, position data is returned to the servo.

[0037] When the control word = 0x32, assign CMD_STATE_WREE to the state machine CMD_STATE and enter the EEPROM write state; When the control word = 0xEA, assign CMD_STATE_RDEE to the state machine CMD_STATE and enter the EEPROM read state; When the control is not in the above three situations, the state machine is kept = CMD_STATE_RDY, and no response (no data is returned); (2) When CMD_STATE = CMD_STATE_WREE, enter the write EEPROM branch; (3) When CMD_STATE = CMD_STATE_RDEE, enter the EEPROM read branch; Embodiment 3 of the present invention is: On the basis of the first embodiment, step S0 is further included before step S1: The servo driver is controlled to read the unique identification code of the motor, and the corresponding motor parameter control table is retrieved according to the unique identification code and the operating mode and parameter setting of the motor are matched.

[0038] From the above description, it can be seen that by reading the unique identification code (Motor Code) of the motor before obtaining the resolver encoding signal, the automatic matching function of the servo drive is realized, ensuring the automatic loading of the operating parameters of each motor, reducing manual intervention, and improving the operating efficiency and adaptability of the system. Specifically, after the servo drive is powered on, the Motor Code stored in the resolver expansion module is read by sending a control word (such as 0xEA). The Motor Code contains the type and parameter table information of the motor. The servo drive automatically calls the corresponding parameter table (such as the number of pole pairs, maximum speed, etc.) according to the read Motor Code to complete the initialization configuration.

[0039] Embodiment 4 of the present invention is: Please refer to Figure 6 A conversion terminal for a resolver coded signal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the conversion of the resolver coded signal are completed.

[0040] For details, please refer to Figure 7 , the terminal includes: (1) Encoder interface The encoder interface connects the resolver encoder to the system. Its main function is to receive the analog signals transmitted by the resolver encoder, including sine waves (SIN) and cosine waves (COS). These signals reflect the current position information or speed information of the motor. In addition, the encoder interface also provides driving voltage for the resolver encoder through the system's excitation signal to ensure that the resolver encoder can work normally and output valid signals.

[0041] (2) Excitation signal generation module The excitation signal generation module is responsible for providing stable excitation voltage and current for the resolver encoder. The module includes a boost power supply and an excitation amplifier circuit. The boost power supply provides the necessary voltage support for the system, and the excitation amplifier circuit further enhances the excitation signal to meet the drive requirements of the resolver encoder and ensure that it can accurately output SIN / COS signals.

[0042] (3) SIN / COS receiving circuit The SIN / COS receiving circuit is the signal acquisition module of the system, which is responsible for receiving the analog signals (SIN and COS) output by the resolver encoder. These signals represent the real-time operating status of the motor. The receiving circuit transmits the signal to the resolver RDC chip for further digital processing and decoding, providing input for subsequent calculations.

[0043] (4) Resolver RDC chip (RDC module) The resolver RDC chip is the core module of the terminal, which is used to analyze the SIN / COS signal transmitted from the resolver encoder. It calculates the motor position information or speed information through the internal analog-to-digital conversion (ADC) and decoding algorithm of the received analog signal, and transmits the processed digital signal to the MCU through the SPI interface. The function of the resolver RDC chip is to achieve accurate decoding and formatted output of the signal.

[0044] (5) Microcontroller unit (MCU) MCU is the control center of the system, responsible for receiving and processing digital signals from the resolver RDC chip. MCU converts the motor's 16-bit position information or speed information into 24-bit absolute encoder format data, adds control fields and CRC check fields, and transmits it to the servo drive through the 485 interface. In addition, MCU is also responsible for operating status monitoring and feedback of system operation or fault information through indicator lights.

[0045] (6) 485 communication interface The 485 communication interface is the data transmission channel between the MCU and the servo drive. The MCU transmits the converted position information or speed information to the servo drive through this interface, and can also receive the control instructions sent by the servo drive. The 485 communication interface has the characteristics of high stability and long transmission distance, ensuring the real-time and reliability of the servo control system.

[0046] (7) Operation / fault indication The operation / fault indication module displays the system operation status or fault information through the indicator light. The green indicator light is used to indicate the module operation status. A long light indicates normal operation, and a flashing light indicates normal communication with the servo drive. The red indicator light is used to display fault information. A flashing light indicates a system fault (such as communication interruption or signal abnormality), and a long light off indicates a normal state.

[0047] (8) Servo drive interface The servo driver interface connects the MCU and the servo driver. It is mainly used to receive the position information or speed information transmitted by the MCU and control the motor's operating mode and parameters based on these data. The servo driver calls the motor parameter table according to the control instructions and data frames received from the interface, and adjusts the motor's operating status to achieve high-precision control.

[0048] In summary, the present invention provides a method and terminal for converting a resolver-encoded signal, which realizes the compatibility of the resolver encoder and the servo drive, and can adapt to different types of encoders without replacing hardware, thereby reducing the system upgrade and maintenance costs. At the same time, the resolver RDC chip is used to perform high-precision decoding and format conversion on the SIN / COS signal, and the stability of the encoder is guaranteed by the excitation signal generation module, which greatly improves the reliability and anti-interference of the signal. The automatic reading and processing function of the MCU realizes the rapid matching and configuration of the motor parameters, and simplifies the debugging and deployment of the servo system. Through the 485 communication interface combined with the CRC check mechanism, the architecture ensures the stability and real-time performance of data transmission, thereby supporting the efficient operation of the servo system, with flexible scalability and strong adaptability, and can meet the needs of various industrial scenarios.

[0049] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for converting a resolver coded signal, characterized in that: Includes steps: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal, and calculating the position information or speed information of the motor; S3, simulating the data protocol of the absolute encoder to convert the number of bits of the position information or speed information; S4, transmitting the converted position information or speed information to the servo driver.

2. The method for converting a resolver coded signal according to claim 1, wherein: The step S3 specifically comprises the following steps: According to the data protocol, the data format of the position information or speed information is converted into a data format readable by the absolute encoder, and control words and CRC check fields are added before and after the data to form a data frame to meet the requirements of the absolute encoder data protocol.

3. The method for converting a resolver coded signal according to claim 2, wherein: The data frame includes: The control field is used to indicate the type of communication instruction; The status field is used to indicate the running status of the conversion process; A data field is used to store the position information or speed information of the motor; CRC check field: used to check the integrity of the data frame.

4. The method for converting a resolver coded signal according to claim 1, wherein: The step S2 specifically includes the following steps: The SIN / COS signal in the analog signal is converted into a digital signal, and the position information or speed information of the motor is obtained by calculation according to the sine-cosine algorithm.

5. The method for converting a resolver coded signal according to claim 1, wherein: The step S1 also includes step S0: The servo driver is controlled to read the unique identification code of the motor, and the corresponding motor parameter control table is retrieved according to the unique identification code and the operation mode and parameter setting of the motor are matched.

6. A conversion terminal for a resolver coded signal, characterized in that: The invention comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the following steps are performed: S1, obtaining the analog signal transmitted by the resolver encoder; S2, decoding the analog signal, and calculating the position information or speed information of the motor; S3, simulating the data protocol of the absolute encoder to convert the number of bits of the position information or speed information; S4, transmitting the converted position information or speed information to the servo driver.

7. The conversion terminal of a resolver coded signal according to claim 6, characterized in that: The step S3 specifically comprises the following steps: According to the data protocol, the data format of the position information or speed information is converted into a data format readable by the absolute encoder, and control words and CRC check fields are added before and after the data to form a data frame to meet the requirements of the absolute encoder data protocol.

8. The conversion terminal of a resolver coded signal according to claim 7, characterized in that: The data frame includes: The control field is used to indicate the type of communication instruction; The status field is used to indicate the running status of the conversion process; The data field is used to store the position information or speed information of the motor; the CRC check field is used to check the integrity of the data frame.

9. The conversion terminal of a resolver coded signal according to claim 6, characterized in that: The step S2 specifically includes the following steps: The SIN / COS signal in the analog signal is converted into a digital signal, and the position information or speed information of the motor is obtained by calculation according to the sine-cosine algorithm.

10. The conversion terminal of a resolver coded signal according to claim 6, characterized in that: The step S1 also includes step S0: The servo driver is controlled to read the unique identification code of the motor, and the corresponding motor parameter control table is retrieved according to the unique identification code and the operation mode and parameter setting of the motor are matched.

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