A method and system for restoring the power-on position of a joint module
By calculating the actual readings and offset values of the encoders at the motor end and the reducer end, the single-turn value of the encoder at the reducer end is corrected and the multi-turn value at the motor end is adjusted, thus solving the problem of inaccurate position recovery of the joint module and achieving more accurate power-on position recovery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TSINO-DYNATRON ELECTRICAL TECH (BEIJING) CO LTD
- Filing Date
- 2024-11-19
- Publication Date
- 2026-07-17
Smart Images
Figure CN119388475B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of robotics technology, and in particular to a method and system for restoring the power-on position of a joint module. Background Technology
[0002] In the fields of modern industrial automation and robotics, the position recovery capability of joint modules is crucial for ensuring the reliability and accuracy of mechanical systems. As core components of robotic arms or other automated equipment, joint modules need to accurately return to their original working position after a power outage or malfunction. This capability not only affects production efficiency but also directly relates to operational safety. In high-precision applications, such as semiconductor manufacturing, precision assembly, or medical surgical robots, the accuracy of position recovery directly impacts product quality control and surgical success rates.
[0003] Typically, dual encoders are used in joint modules. The first encoder measures the position at the motor end, and the second encoder measures the position at the reducer end. To save cost and space, both the motor and reducer ends use encoders without batteries. The patent CN118528326.A, "A Method for Determining the Joint Position of a Robot," records and saves the readings of both encoders at the factory. Each time the robot is powered on, the actual encoded data is read, and the number of overflow revolutions of the motor is calculated based on the factory-recorded encoder readings and the actual encoded data read upon power-on. The actual angle of joint rotation is then determined based on the number of overflow revolutions. This method is prone to errors due to mechanical reasons causing the factory-saved absolute zero point to deviate from the actual position, leading to inaccurate position determination. Furthermore, since both encoders in this method are single-turn encoders, if the encoder's operating range exceeds 360 degrees, the position cannot be determined solely from the motor's encoder readings, resulting in incorrect power-on position. Summary of the Invention
[0004] Based on this, and in response to the aforementioned technical problems, a method and system for restoring the power-on position of a joint module are provided to solve the problem of inaccurate position determination using existing position determination methods.
[0005] A first aspect includes a method for restoring the power-on position of a joint module, the method comprising:
[0006] Obtain the encoder values at the motor end and the reducer end upon restart; the encoder value is the single-turn value ST.
[0007] The single-turn value of the reducer encoder is calculated based on the pre-saved first offset value, the single-turn value of the reducer encoder, and the pre-saved reduction ratio of the motor encoder and reducer encoder. The corrected position Pos2 of the motor encoder is then recorded as the first conversion position. The corrected multi-turn value of the motor encoder is then calculated based on the first conversion position. The first offset value is the offset value of the motor encoder and reducer encoder at zero point before they start running.
[0008] Calculate the single-turn value of the encoder at the motor end and convert it to the correction position Pos1 of the encoder at the reducer end, which is recorded as the second conversion position. Determine whether the difference between the first conversion position and the second conversion position is greater than a preset error threshold. If it is greater, add 1 to the corrected multi-turn value of the encoder at the motor end to obtain the final multi-turn value of the encoder at the motor end. If it is less than, subtract 1 from the corrected multi-turn value of the encoder at the motor end to obtain the final multi-turn value of the encoder at the motor end.
[0009] The power-on recovery position is calculated based on the final multi-turn value of the encoder at the motor end and the read single-turn value.
[0010] Optionally, in the above scheme, the method further includes:
[0011] During operation, the single-turn value ST of the encoder at the reducer end and the encoder at the motor end is obtained when the encoder at the reducer end passes through the zero point again;
[0012] The recalculated offset values of the encoder at the motor end and the encoder at the reducer end are recorded as the second offset value;
[0013] If the second offset value minus the first offset value is greater than a preset value, then the second offset value is saved as the first offset value.
[0014] In the above scheme, optionally, the first offset value and the second offset value are calculated in the following way:
[0015] Calculate the correction position of the single-turn value actually measured by the encoder at the motor end and convert it to the reducer end. Then, calculate the difference between the correction position of the single-turn value actually measured by the encoder at the motor end and the single-turn value actually measured by the encoder at the reducer end using the following formula. This difference is the offset value.
[0016] MTOffset = ST2 实 –ST1 实 / ((2 R1 / 2 R2 )*n)
[0017] Among them, ST2 实 ST1 is the single-turn value actually measured by the encoder at the reducer end. 实R1 is the actual single-turn value measured by the encoder at the motor end; R2 is the resolution of the encoder at the motor end; and n is the reduction ratio of the encoder at the motor end and the encoder at the reducer end.
[0018] In the above scheme, optionally, the correction position Pos2 of the encoder at the reducer end, converted to the encoder at the motor end, is calculated using the following formula:
[0019] Pos2=(ST2 实 +MT2 实 *2 R1 –MTOffset1)*(2 R1 / 2 R2 )*n
[0020] Where MTOffset1 is the first offset value; MT2 实 The multi-turn value is determined based on the single-turn value ST2 obtained from the actual measurement of the encoder at the reducer end.
[0021] In the above scheme, optionally, the corrected multi-turn value of the encoder at the motor end is calculated based on the first folded position using the following formula:
[0022] MT1 修 =Pos2 / 2 R1
[0023] Where pos2 is the first folding position, MT1 修 This is the corrected multi-turn value of the encoder at the motor end.
[0024] Optionally, in the above scheme, the error threshold is 0.5*2^R1.
[0025] In the above scheme, optionally, the calculation of the power-on recovery position based on the final multi-turn value of the encoder at the motor end and the read single-turn value is performed using the following formula:
[0026] ActPos = (ST1) 实 +MT1 修 *2 R1 )
[0027] Among them, ST1 实 MT1 represents the actual single-turn value read by the encoder at the motor end. 修 This is the corrected multi-turn value of the encoder at the motor end.
[0028] Secondly, a power-on position recovery system for a joint module, the system comprising:
[0029] Data acquisition module: used to acquire the encoder values at the motor end and the reducer end during restart; the encoder value is the single-turn value ST;
[0030] The multi-turn value correction module for the motor-end encoder is used to calculate the correction position Pos2 of the motor-end encoder based on the pre-saved first offset value, the single-turn value of the reducer-end encoder, and the pre-saved reduction ratio of the motor-end encoder and the reducer-end encoder. This correction position is recorded as the first conversion position. Then, the corrected multi-turn value of the motor-end encoder is calculated based on the first conversion position. The first offset value is the offset value of the motor-end encoder and the reducer-end encoder at the zero point before they start running.
[0031] The final multi-turn count calculation module for the motor-end encoder is used to calculate the single-turn value of the motor-end encoder converted to the correction position Pos1 of the reducer-end encoder, which is denoted as the second conversion position. It determines whether the difference between the first conversion position and the second conversion position is greater than a preset error threshold. If it is greater, the corrected multi-turn value of the motor-end encoder is increased by 1 to obtain the final multi-turn value of the motor-end encoder. If it is less than, the corrected multi-turn value of the motor-end encoder is decreased by 1 to obtain the final multi-turn value of the motor-end encoder.
[0032] Power-on recovery position calculation module: used to calculate the power-on recovery position based on the final multi-turn value of the encoder at the motor end and the read single-turn value.
[0033] Thirdly, a computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the power-on position recovery method for a joint module described in the first aspect.
[0034] Fourthly, a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the power-on position recovery method for a joint module described in the first aspect.
[0035] This application has at least the following beneficial effects:
[0036] This application calculates the offset value based on the actual readings of the motor-end encoder and the reducer-end encoder before operation begins. Then, after a power outage and restart, the single-turn value measured by the reducer-end encoder is corrected using the offset value, and the single-turn value of the reducer-end encoder is converted to the corrected position of the motor-end encoder. Based on the corrected multi-turn value of the motor-end encoder, and comparing the difference between the corrected positions Pos1 and Pos2 of the single-turn value of the motor-end encoder converted to the reducer-end encoder with a preset error, the corrected multi-turn value of the motor-end encoder is incremented or decremented by 1 to obtain the final multi-turn value of the motor-end encoder. The power-on recovery position is then calculated based on the final multi-turn value of the motor-end encoder and the read single-turn value. Therefore, this method eliminates the need to record and save the two encoder readings at the factory; the power-on recovery position can be calculated using only the actual encoder readings after power-on and the pre-obtained offset value, resulting in a more accurate calculation. Attached Figure Description
[0037] Figure 1 This is a flowchart of a method for restoring the power-on position of a joint module according to an embodiment of this application. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0039] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," "third," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "comprising," "including," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).
[0040] In one embodiment, such as Figure 1 As shown, a method for restoring the power-on position of a joint module is provided, including the following steps:
[0041] Step S1: Obtain the encoder values at the motor end and the reducer end upon restart; the encoder value is the single-turn value ST.
[0042] Step S2: Calculate the correction position Pos2 of the motor encoder based on the pre-saved first offset value, the single-turn value of the encoder at the reducer end, and the pre-saved reduction ratio of the encoder at the motor end and the encoder at the reducer end. This correction position is recorded as the first conversion position. Then, calculate the corrected multi-turn value of the encoder at the motor end based on the first conversion position. The first offset value is the offset value of the encoder at the motor end and the encoder at the reducer end at the zero point before they start running.
[0043] Step S3: Calculate the single-turn value of the motor-end encoder and convert it to the correction position Pos1 of the reducer-end encoder, which is recorded as the second conversion position. Determine whether the difference between the first conversion position and the second conversion position is greater than the preset error threshold. If it is greater, add 1 to the corrected multi-turn value of the motor-end encoder to obtain the final multi-turn value of the motor-end encoder. If it is less than 1, subtract 1 from the corrected multi-turn value of the motor-end encoder to obtain the final multi-turn value of the motor-end encoder.
[0044] Step S4: Calculate the power-on recovery position based on the final multi-turn value of the encoder at the motor end and the read single-turn value.
[0045] The joint module of this invention uses the motor-side encoder Ecd1 to achieve position loop control, which has better control bandwidth and position accuracy. Therefore, the position ActPos value needs to be converted to the motor side when power is restored, with the unit Inc1.
[0046] The motor-side encoder Ecd1 has a resolution of R1 bits and a single-turn value ST1 ranging from 0 to 2^R1-1.
[0047] The encoder Ecd2 at the reducer end has a resolution of R2 bits and a single-turn value ST2 range of 0 to 2^R2-1.
[0048] The mechanical reduction ratio between the motor end and the reducer end of the driver is n.
[0049] This invention utilizes the reduction ratio n to recover the number of revolutions MT1 of Ecd1 based on the Ecd2 data ST2 at the reducer end, thereby obtaining the power-on position value ActPos.
[0050] Upon power-up, the single-turn value ST2 (unit Inc2) of Ecd2 is converted to the position Pos2 (unit Inc1) at the motor end to directly calculate the integer multi-turn value MT1 of Ecd1.
[0051] Pos2 = (ST2) 实 + MT2 实 * 2 R1 )* (2 R1 / 2 R2 ) * n (1)
[0052] MT1修 = Pos2 / 2 20 (2)
[0053] MT2 is the multi-turn value of Ecd2, which takes the value of 0 or -1, corresponding to an operating range of ±180 degrees.
[0054] The power-on recovery position ActPos is calculated as follows:
[0055] ActPos = (ST1) 实 + MT1 修 *2 R1 (3)
[0056] Formula (2) only requires readings from the two encoders at the time of power-on to calculate the position ActPos after power-on, without needing to record the running information before power-off, thus improving the reliability of power-on position recovery.
[0057] When calculating the error using the encoder values at the motor end and the reducer end, two types of errors will occur. The error Err1, which is within one revolution (360 degrees) of the reducer end encoder reading ST2, is a larger error, while the error Err2, which is within one revolution of the reducer end encoder reading, is smaller. The Err1 value is periodically correlated with ST2, and the Err2 value is periodically correlated with ST1.
[0058] Considering Err1, before starting operation, the reading error PosErr of the two encoders is calculated and converted to the reducer side to obtain the encoder zero offset value MTOffset (unit Inc2), and the encoder zero offset value MTOffset is saved to EEPROM.
[0059] MTOffset = ST2 实 – ST1 实 / ((2 R1 / 2 R2 (4)
[0060] Upon restart, the encoder Ecd2 reading ST2 at the reducer end is subtracted from the corrected Pos2 calculated by MTOffset.
[0061] Pos2 = (ST2) 实 + MT2 实 * 2 R1 – MTOffset1)* (2 R1 / 2 R2 Therefore, the calculation of the multi-turn value MT1 of the encoder Ecd1 at the motor end is corrected as follows:
[0062] MT1 修= Pos2 / 2^20 (6)
[0063] Considering the small error Err2, upon power-up, it is determined whether the difference between the folded positions of the two encoders is greater than ErrTh, and MT1 is adjusted accordingly. 修 , where ErrTh = 0.5 * 2^R1.
[0064] MT1 修 = MT1+1, (Pos2-Pos1> ErrTh) (7)
[0065] MT1=MT1-1, (Pos1-Pos2> ErrTh) (8)
[0066] Then, the power-on position ActPos can be obtained according to formula (9).
[0067] ActPos = (ST1) 实 + MT1 修 *2 R1 (9)
[0068] The operating range determination in this application is achieved by setting ST2=0 on the encoder Ecd2 at the reducer end after the joint module is assembled, thus determining the 360-degree operating range. During actual operation, the mechanical encoder increments or decrements the multi-turn value MT2 at the zero-crossing point according to the operating direction. That is, if MT2=0 after power-on, the operating range is 360 degrees; if MT2=-1, the direction is decreasing from 0 degrees; and if MT2=1, the direction is increasing from 360 degrees. The number of turns recorded on the reducer side can then be used to determine whether the operating range exceeds 360 degrees.
[0069] In the aforementioned method for restoring the power-on position of a joint module, an offset value is calculated based on the actual readings of the encoders at the motor and reducer ends before operation begins. Then, after a power outage and restart, the single-turn value measured by the reducer encoder is corrected using the offset value, and the single-turn value of the reducer encoder is converted to the corrected position of the motor encoder. Based on the corrected multi-turn value of the motor encoder, and considering whether the difference between the corrected positions Pos1 and Pos2 of the single-turn value of the motor encoder converted to the reducer encoder is greater than a preset error, the corrected multi-turn value of the motor encoder is incremented or decremented by 1 to obtain the final multi-turn value of the motor encoder. The power-on recovery position is then calculated based on the final multi-turn value of the motor encoder and the read single-turn value. Therefore, this method eliminates the need to record and save the encoder readings at the factory; the power-on recovery position can be calculated using only the actual encoder readings after power-on and the pre-obtained offset value, resulting in a more accurate calculation.
[0070] In one embodiment, the method further includes:
[0071] During operation, the single-turn value ST of the encoder at the reducer end and the encoder at the motor end is obtained when the encoder at the reducer end passes through the zero point again;
[0072] The recalculated offset values of the encoder at the motor end and the encoder at the reducer end are recorded as the second offset value;
[0073] If the second offset value minus the first offset value is greater than a preset value, then the second offset value is saved as the first offset value.
[0074] Specifically, in actual operation, the current EcdOffset (in Inc2) is calculated based on the real-time PosErr at the zero-crossing point of Ecd2. If the difference between EcdOffset and the saved MTOffset is greater than a certain value, an alarm is triggered; at this time, the current EcdOffset needs to be updated to EEPROM as the correct MTOffset.
[0075] In one embodiment, the first offset value and the second offset value are calculated in the following manner:
[0076] Calculate the correction position of the single-turn value actually measured by the encoder at the motor end and convert it to the reducer end. Then, calculate the difference between the correction position of the single-turn value actually measured by the encoder at the motor end and the single-turn value actually measured by the encoder at the reducer end using the following formula. This difference is the offset value.
[0077] MTOffset = ST2 实 – ST1 实 / ((2 R1 / 2 R2 (10)
[0078] Among them, ST2 实 ST1 is the single-turn value actually measured by the encoder at the reducer end. 实 R1 is the actual single-turn value measured by the encoder at the motor end; R2 is the resolution of the encoder at the motor end; and n is the reduction ratio of the encoder at the motor end and the encoder at the reducer end.
[0079] In one embodiment, the correction position Pos2 of the encoder at the reducer end, converted to the encoder at the motor end, is calculated using the following formula:
[0080] Pos2 = (ST2) 实 + MT2 实 * 2 R1 – MTOffset1)* (2 R1 / 2R2 ) * n (11)
[0081] Where MTOffset1 is the first offset value; MT2 实 The multi-turn value is determined based on the single-turn value ST2 obtained from the actual measurement of the encoder at the reducer end.
[0082] In one embodiment, the corrected multi-turn value of the motor-end encoder based on the first folded position is calculated using the following formula:
[0083] MT1 修 = Pos2 / 2 R1 (12)
[0084] Where pos2 is the first folding position, MT1 修 This is the corrected multi-turn value of the encoder at the motor end.
[0085] In one embodiment, the error threshold is 0.5*2^R1.
[0086] In one embodiment, the calculation of the power-on recovery position based on the final multi-turn value and the read single-turn value of the encoder at the motor end is performed using the following formula:
[0087] ActPos = (ST1) 实 + MT1 修 *2 R1 (13)
[0088] Among them, ST1 实 MT1 represents the actual single-turn value read by the encoder at the motor end. 修 This is the corrected multi-turn value of the encoder at the motor end.
[0089] After the joint module is assembled, setting ST2=0 for Ecd2 determines the 360-degree operating range. During actual operation, the mechanical encoder increments or decrements the multi-turn value MT2 by 1 at the zero-crossing point according to the direction of operation.
[0090] If MT2 = 0 after power-on, the operating range is 360 degrees; if MT2 = -1, the direction is decreasing from 0 degrees; and if MT2 = 1, the direction is increasing from 360 degrees. The number of gearbox rotations saved can be used to determine whether the operating range exceeds 360 degrees.
[0091] In one embodiment, a power-on position recovery system for a joint module is provided, the system comprising:
[0092] Data acquisition module: used to acquire the encoder values at the motor end and the reducer end during restart; the encoder value is the single-turn value ST;
[0093] The multi-turn value correction module for the motor-end encoder is used to calculate the correction position Pos2 of the motor-end encoder based on the pre-saved first offset value, the single-turn value of the reducer-end encoder, and the pre-saved reduction ratio of the motor-end encoder and the reducer-end encoder. This correction position is recorded as the first conversion position. Then, the corrected multi-turn value of the motor-end encoder is calculated based on the first conversion position. The first offset value is the offset value of the motor-end encoder and the reducer-end encoder at the zero point before they start running.
[0094] The final multi-turn count calculation module for the motor-end encoder is used to calculate the single-turn value of the motor-end encoder converted to the correction position Pos1 of the reducer-end encoder, which is denoted as the second conversion position. It determines whether the difference between the first conversion position and the second conversion position is greater than a preset error threshold. If it is greater, the corrected multi-turn value of the motor-end encoder is increased by 1 to obtain the final multi-turn value of the motor-end encoder. If it is less than, the corrected multi-turn value of the motor-end encoder is decreased by 1 to obtain the final multi-turn value of the motor-end encoder.
[0095] Power-on recovery position calculation module: used to calculate the power-on recovery position based on the final multi-turn value of the encoder at the motor end and the read single-turn value.
[0096] The advantages of this application are:
[0097] 1) Dual encoders increase system redundancy. When one encoder fails, the other can provide valid position information.
[0098] 2) Solve the problem of position loss caused by the encoder deviating from the original zero point in practical applications.
[0099] 3) It can be adapted to different application scenarios and calibrated flexibly.
[0100] 4) It does not require saving location information when power is off; the location can be restored when power is on, reducing the complexity of power-off operations.
[0101] 5) It has a self-calibration function and can trigger an alarm in abnormal situations.
[0102] 6) It can provide monitoring with an operating range of more than 360 degrees, improving system security and reliability.
[0103] 7) It does not increase the hardware complexity of the product, nor does it affect the dynamic performance of the system.
[0104] For specific limitations regarding the power-on position recovery system for a joint module, please refer to the limitations of the power-on position recovery method for a joint module described above, which will not be repeated here. Each module in the aforementioned power-on position recovery system for a joint module can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.
[0105] In one embodiment, a computer device is provided, which may be a server. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements the power-on position recovery method for a joint module described above.
[0106] In one embodiment, a computer program product is also provided, including a computer program / instruction relating to all or part of the processes in the methods of the above embodiments.
[0107] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.
[0108] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0109] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method for restoring the power-on position of a joint module, characterized in that, The method includes: Obtain the encoder values at the motor end and the reducer end upon restart; the encoder value at the motor end is the single-turn value ST. The single-turn value of the reducer encoder is calculated based on the pre-saved first offset value, the single-turn value of the reducer encoder, and the pre-saved reduction ratio of the motor encoder and reducer encoder. The corrected position Pos2 of the motor encoder is then recorded as the first conversion position. The corrected multi-turn value of the motor encoder is then calculated based on the first conversion position. The first offset value is the offset value of the motor encoder and reducer encoder at zero point before they start running. Calculate the single-turn value of the encoder at the motor end and convert it to the correction position Pos1 of the encoder at the reducer end, which is recorded as the second conversion position. Determine whether the difference between the first conversion position and the second conversion position is greater than a preset error threshold. If it is greater, add 1 to the corrected multi-turn value of the encoder at the motor end to obtain the final multi-turn value of the encoder at the motor end. If it is less than, subtract 1 from the corrected multi-turn value of the encoder at the motor end to obtain the final multi-turn value of the encoder at the motor end. The power-on recovery position is calculated based on the final multi-turn value of the encoder at the motor end and the single-turn value read. The method further includes: During operation, the single-turn value ST of the encoder at the reducer end and the encoder at the motor end is obtained when the encoder at the reducer end passes through the zero point again; The recalculated offset values of the encoder at the motor end and the encoder at the reducer end are recorded as the second offset value; If the second offset value minus the first offset value is greater than a preset value, then the second offset value is saved as the first offset value; The first offset value and the second offset value are calculated in the following manner: Calculate the correction position of the single-turn value actually measured by the encoder at the motor end and convert it to the reducer end. Then, calculate the difference between the correction position of the single-turn value actually measured by the encoder at the motor end and the single-turn value actually measured by the encoder at the reducer end using the following formula. This difference is the offset value. ， in, This is the single-turn value actually measured by the encoder at the reducer end. The actual single-turn value measured by the encoder at the motor end; R1 is the resolution of the encoder at the motor end, R2 is the resolution of the encoder at the reducer end, and n is the reduction ratio of the encoder at the motor end and the encoder at the reducer end.
2. The power-on position recovery method for a joint module according to claim 1, characterized in that, The correction position Pos2 of the encoder at the reducer end, converted to the encoder at the motor end, is calculated using the following formula: ， in, This is the first offset value; The multi-turn value is determined based on the single-turn value ST2 obtained from the actual measurement of the encoder at the reducer end.
3. The power-on position recovery method for a joint module according to claim 1, characterized in that, The corrected multi-turn value of the encoder at the motor end, based on the first folded position, is calculated using the following formula: ， Where pos2 is the first folding position. This is the corrected multi-turn value of the encoder at the motor end.
4. The power-on position recovery method for a joint module according to claim 1, characterized in that, The error threshold is .
5. The power-on position recovery method for a joint module according to claim 1, characterized in that, The power-on recovery position is calculated based on the final multi-turn value and the read single-turn value of the encoder at the motor end using the following formula: ， in, This is the actual single-turn value read by the encoder at the motor end. This is the corrected multi-turn value of the encoder at the motor end.
6. A power-on position recovery system for a joint module, used to execute the power-on position recovery method for a joint module according to any one of claims 1-5, characterized in that, The system includes: Data acquisition module: used to acquire the encoder values at the motor end and the encoder values at the reducer end during restart; the encoder value at the motor end is the single-turn value ST; The multi-turn value correction module for the motor-end encoder is used to obtain the single-turn value ST of the reducer-end encoder and the motor-end encoder when the reducer-end encoder passes through the zero point again during operation; recalculate the offset value of the motor-end encoder and the reducer-end encoder, and record it as the second offset value; if the second offset value minus the first offset value is greater than a preset value, then the second offset value is saved as the first offset value; the first offset value and the second offset value are calculated in the following way: calculate the correction position of the actual single-turn value measured by the motor-end encoder converted to the reducer end, and calculate the difference between the correction position of the actual single-turn value measured by the motor-end encoder converted to the reducer end and the actual single-turn value measured by the reducer end encoder using the following formula as the offset value; ， in, This is the single-turn value actually measured by the encoder at the reducer end. R1 is the actual single-turn value measured by the encoder at the motor end; R2 is the resolution of the encoder at the motor end; and n is the reduction ratio between the encoder at the motor end and the encoder at the reducer end. And it is used to calculate the correction position Pos2 of the motor encoder based on the pre-saved first offset value, the single-turn value of the reducer encoder, and the pre-saved reduction ratio of the motor encoder and the reducer encoder, and record it as the first conversion position. Then, it calculates the corrected multi-turn value of the motor encoder based on the first conversion position. The first offset value is the offset value of the motor encoder and the reducer encoder at the zero point before they start running. The final multi-turn count calculation module for the motor-end encoder is used to calculate the single-turn value of the motor-end encoder converted to the correction position Pos1 of the reducer-end encoder, which is denoted as the second conversion position. It determines whether the difference between the first conversion position and the second conversion position is greater than a preset error threshold. If it is greater, the corrected multi-turn value of the motor-end encoder is increased by 1 to obtain the final multi-turn value of the motor-end encoder. If it is less than, the corrected multi-turn value of the motor-end encoder is decreased by 1 to obtain the final multi-turn value of the motor-end encoder. Power-on recovery position calculation module: used to calculate the power-on recovery position based on the final multi-turn value of the encoder at the motor end and the read single-turn value.
7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.
8. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 5.