Method and apparatus for accurate positioning of a robot joint

Abstract

The application discloses a kind of accurate positioning method and device of robot joint, method includes: obtaining the first position signal of permanent magnet motor collected by resolver and the second position signal of permanent magnet motor collected by hall sensor, and first position signal and second position signal are respectively stored in the form of N-bit binary number;The low M bit of second position signal is used to the low M bit of first position signal is weighted replacement, obtain the motor weighted position signal after synthesis, in order to realize accurate positioning to robot joint, wherein, M < N.The application replaces the data of part of precision of resolver by part of high-precision data of hall sensor, obtains the motor weighted position signal after synthesis, to obtain accurate motor position signal, and then realize accurate positioning of robot joint.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, specifically relating to a method and apparatus for precise positioning of robot joints. Background Technology

[0002] Robot joints are mechanisms that enable relative movement between the various components of a robot. Robot joints are typically driven by ultrasonic motors, servo motors, and permanent magnet motors. While permanent magnet motors can ideally achieve zero torque fluctuation operation when driving robot joints, their performance is significantly reduced in practical applications due to factors such as imperfect back electromotive force waveforms. Therefore, to improve the control performance of permanent magnet motors, accurate position information is needed to achieve precise positioning of the robot joints.

[0003] A resolver is an angle-measuring element based on the principle of electromagnetic induction, used in articulated motor systems to detect the rotation angle of the output shaft. Considering the positional coupling between the motor rotor and the output shaft, a reducer is typically used in conjunction with the resolver to estimate the rotor position. However, using only the resolver signal to estimate the rotor position introduces a predetermined error. This error primarily consists of two parts: nonlinear error caused by the reducer's backlash and quantization error from the angle-measuring system. The error caused by the reducer's backlash mainly occurs after the motor switches direction and manifests as a constant offset with a certain amplitude. The quantization error arises from the limited accuracy of the resolver's angle-measuring quantization, resulting in a missing position signal. The following formulas describe the rotor position estimation error using specific parameters:

[0004] Δθ=pi+Δθ BL (1)

[0005] Where Δθ represents the fundamental error in the electronic rotor position estimation, Δθ BL denoted by p, representing the bias constant introduced by the return clearance of the reducer; p represents the number of pole pairs of the permanent magnet motor; and i represents the reduction ratio of the reducer.

[0006] It is evident that although the angular measurement accuracy of the rotary transformer is very high, its quantization error, after being amplified by the reduction ratio of the reducer and the number of motor pole pairs, can no longer be ignored. Therefore, how to provide an effective solution to overcome the problem of insufficient robot joint positioning caused by the quantization error of the rotary transformer has become an urgent problem to be solved in the existing technology. Summary of the Invention

[0007] The purpose of this invention is to provide a precise positioning method and apparatus for robot joints, in order to solve the technical problem of insufficient robot joint positioning caused by the quantization error of the rotary transformer in the prior art, so as to obtain the precise motor position and thus accurately position the robot joints.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for precise positioning of robot joints, comprising:

[0010] The first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor are acquired, and the first position signal and the second position signal are stored in the form of N-bit binary numbers respectively.

[0011] The lower M bits of the first position signal are weighted and replaced by the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, so as to achieve precise positioning of the robot joint, where M < N.

[0012] Based on the above-disclosed content, the position signals of the motor system are collected by a rotary transformer and a Hall sensor, and stored in binary form. Then, based on the accuracy of the measurement signals from the rotary transformer and the Hall sensor at each position in the N-bit binary number, the high-precision data from the Hall sensor is used to replace the less accurate data from the rotary transformer, resulting in a synthesized weighted position signal for the motor. This yields a precise motor position signal. Since the motor is the driving mechanism for the robot joints, precise positioning of the robot joints can be achieved simultaneously with precise motor positioning, thus overcoming the technical problem of insufficient robot joint positioning caused by the quantization error of the rotary transformer.

[0013] In one possible design, before acquiring the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, the following steps are also included:

[0014] During signal detection, the offset between the rotary transformer and the Hall sensor is acquired, and the phase of the rotary transformer or the Hall sensor is corrected based on the offset.

[0015] Based on the above-disclosed information, since there may be a phase inconsistency between the rotary transformer and the Hall sensor during the signal detection process, phase correction is required to make the two phases consistent in order to improve the accuracy of the signal detection results.

[0016] One possible design also includes:

[0017] The corresponding error correction bits are set in the lower M bits of the first position signal and the second position signal respectively, and the motor weighted position signal is corrected according to the comparison result of the error correction bits.

[0018] Based on the above-disclosed information, carry errors caused during signal synthesis can be overcome, ensuring the accuracy of the synthesized weighted position signal of the motor.

[0019] In one possible design, acquiring the first position signal of the permanent magnet motor from the rotary transformer and the second position signal of the permanent magnet motor from the Hall sensor includes:

[0020] The rotation angle signal of the motor output shaft measured by the rotary transformer is obtained, and the rotation angle signal is converted into the first rotor position signal;

[0021] Acquire the second rotor position signal of the motor rotor measured by the Hall sensor.

[0022] In one possible design, acquiring the first position signal of the permanent magnet motor from the rotary transformer and the second position signal of the permanent magnet motor from the Hall sensor includes:

[0023] Acquire the first output shaft position signal of the motor output shaft measured by the rotary transformer;

[0024] The motor rotor position signal measured by the Hall sensor is acquired, and the electronic rotor position signal is converted into the second output shaft position signal.

[0025] In one possible design, the lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized weighted position signal of the motor, including:

[0026] The high four bits of the first rotor position signal are selected as the reliable bits, and the low eight bits of the second rotor position signal are selected as the accurate bits. At this time, N=12.

[0027] The lower eight bits of the first rotor position signal are weighted and replaced with the lower eight bits of the second rotor position signal, and the replaced first rotor position signal is used as the synthesized weighted rotor position signal of the motor.

[0028] In one possible design, the lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized weighted position signal of the motor, including:

[0029] The high eleven bits of the first output shaft position signal are selected as the reliable bits, and the low five bits of the second output shaft position signal are selected as the precise bits. At this time, N=16.

[0030] The lower five bits of the first output shaft position signal are weighted and replaced with the lower five bits of the second output shaft position signal, and the replaced first output shaft position signal is the synthesized weighted position signal of the motor output shaft.

[0031] In one possible design, the offset between the resolver and the Hall sensor is acquired during signal detection, and phase correction is performed on the resolver or Hall sensor based on the offset, including:

[0032] At the moment of commutation of the permanent magnet motor, obtain the first offset between the estimated position of the rotary transformer and the detected position of the Hall sensor;

[0033] Adding the first offset to the estimated position of the rotary transformer yields the phase-corrected estimated position of the rotary transformer.

[0034] In one possible design, the offset between the resolver and the Hall sensor is acquired during signal detection, and phase correction is performed on the resolver or Hall sensor based on the offset, including:

[0035] The second offset between the Hall sensor's estimated position and the rotary transformer's detected position is obtained when the rotary transformer detects a change in the motor output shaft angle.

[0036] Adding the second offset to the position detected by the rotary transformer yields the estimated position of the Hall sensor after phase correction.

[0037] In a second aspect, the present invention provides a precise positioning device for a robot joint, comprising:

[0038] The signal acquisition module is used to acquire the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, and store the first position signal and the second position signal in the form of N-bit binary numbers respectively.

[0039] The signal weighting module is used to replace the lower M bits of the first position signal with the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, so as to achieve precise positioning of the robot joint, where M < N.

[0040] Thirdly, the present invention provides a computer device comprising a memory, a processor, and a transceiver connected in sequence and communication, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute a precise positioning method for robot joints as described in any possible design of the first aspect.

[0041] Fourthly, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, perform a precise positioning method for robot joints as described in any possible design of the first aspect.

[0042] Fifthly, the present invention provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform a precise positioning method for a robot joint as described in any possible design of the first aspect. Attached Figure Description

[0043] Figure 1 A flowchart of the precise positioning method for robot joints provided by the present invention;

[0044] Figure 2 This invention provides a schematic diagram of the principle of position and phase correction for a rotary transformer.

[0045] Figure 3 A schematic diagram of the Hall sensor position estimation phase correction principle provided by the present invention;

[0046] Figure 4 A schematic diagram illustrating the synthesis principle of the weighted position signal of the motor rotor provided by this invention;

[0047] Figure 5 A schematic diagram illustrating the synthesis principle of the weighted position signal of the motor output shaft provided by this invention;

[0048] Figure 6 The simulation verification curve of the weighted position signal of the motor output shaft provided by the present invention. Detailed Implementation

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0050] Example

[0051] In order to obtain precise motor positions for accurate positioning of robot joints and overcome the technical problem of insufficient robot joint positioning caused by quantization errors of rotary transformers in the prior art, this application provides a precise positioning method and apparatus for robot joints. The method uses motor position signals collected by Hall sensors to partially replace motor position signals collected by rotary transformers to obtain precise motor position signals, thereby enabling accurate positioning of robot joints.

[0052] Before describing the precise positioning method for robot joints provided by this invention, the feasibility of the precise positioning method will be explained in conjunction with the background art, as follows:

[0053] Since the positioning accuracy of the robot's joint motor drive system is a crucial indicator of robot performance, any positioning error in the motor system during robot operation can prevent the robot's end effector from reaching the desired position, resulting in significant time spent on adjustments. By analyzing the factors affecting joint positioning accuracy, it can be concluded that the positioning accuracy of the joint motor drive system can be improved through information weighting. Specifically, the positioning accuracy of the joint motor system mainly depends on the motor's positioning capability and the detection accuracy of the position sensor. In high-precision position control systems, the detection accuracy of a single-pole rotary transformer is often insufficient, requiring the addition of an additional multi-pole rotary transformer or inductive synchronizer to subdivide the output shaft angle. Weighting the position information improves the position detection accuracy. Considering the structural characteristics of the position sensor in the joint motor drive system, this embodiment supplements the rotary transformer with information returned by a Hall effect position sensor.

[0054] Furthermore, since permanent magnet motors have six conduction states, the motor rotor can be fixed in a specific position, indicating a positioning accuracy of 60° electrical angle. Combining this with the number of pole pairs and the reduction ratio of the reducer, the positioning accuracy of the motor system is 0.54°. On the other hand, the joint system's drive system uses closed-loop position control, and its position detection capability directly affects the joint's positioning accuracy. The output shaft position is mainly detected by a rotary transformer, with an angle conversion resolution of 0.18°. Therefore, if the motor rotor angle is determined solely by the commutation position measured by the Hall effect position sensor, this angle resolution is consistent with the motor's positioning accuracy, at 0.54°. It is evident that, besides the rotary transformer's own parameters, the number of pole pairs and the reducer ratio significantly influence this method. When the motor system parameters satisfy the following formula, the output shaft position can be directly calculated from the discrete positions of the motor rotor, thereby improving the joint system's position detection capability.

[0055]

[0056] in, —Accuracy of mechanical angle detection for the output shaft of a rotary transformer;

[0057] —The accuracy of Hall effect sensor in detecting the electrical angle of motor rotor.

[0058] Therefore, if a rotor position estimation method based on Hall signals is adopted, the accuracy of motor system output shaft position detection can be improved when the control system is unable to meet the above conditions.

[0059] It should be noted that the precise positioning method for robot joints provided in this application can be applied to any intelligent terminal device for signal synthesis. These intelligent terminal devices include, but are not limited to, smartphones, tablets, industrial computers, and laptops, etc., and are not limited here. For ease of description, unless otherwise specified, this application uses an industrial computer as the execution subject in its embodiments. It is understood that the execution subject does not constitute a limitation on the embodiments of this application; other terminal devices may be used as the execution subject in some other embodiments.

[0060] like Figures 1-5 The diagram shown is a flowchart and schematic diagram of a precise positioning method for robot joints provided in this application embodiment. The precise positioning method for robot joints includes, but is not limited to, steps S1 to S2:

[0061] Step S1. Obtain the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, and store the first position signal and the second position signal in N-bit binary form respectively;

[0062] In one possible design of step S1, acquiring the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor includes:

[0063] Step S11a. Obtain the rotation angle signal of the motor output shaft measured by the rotary transformer, and convert the rotation angle signal into a first rotor position signal;

[0064] It should be noted that since the rotary transformer is used in the robot joint system to detect the rotation angle of the output shaft, after the rotation angle is measured, it needs to be converted into a rotor position signal based on a preset position signal conversion method, so that it can be combined with the rotor position signal measured by the Hall sensor. The preset position signal conversion method is an existing conversion method, and its specific principle will not be elaborated here.

[0065] Step S12a. Obtain the second rotor position signal of the motor rotor measured by the Hall sensor.

[0066] In another possible design of step S1, acquiring the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor includes:

[0067] S11b. Obtain the first output shaft position signal of the motor output shaft measured by the rotary transformer;

[0068] S12b. Acquire the motor rotor position signal measured by the Hall sensor and convert the electronic rotor position signal into the second output shaft position signal.

[0069] It should be noted that since the Hall sensor is used for the motor rotor position signal in the robot joint system, after the motor rotor position signal is measured, it needs to be converted into the output shaft position signal based on a preset position signal conversion method, so that it can be combined with the output shaft position signal measured by the rotary transformer. The preset position signal conversion method is an existing conversion method, and its specific principle will not be elaborated here.

[0070] Preferably, before step S1, since there may be a phase inconsistency between the rotary transformer and the Hall sensor during signal detection, phase correction is needed to make their phases consistent in order to improve the accuracy of the signal detection results. Therefore, the method further includes:

[0071] Step S0. Obtain the offset between the rotary transformer and the Hall sensor during signal detection, and perform phase correction on the rotary transformer or Hall sensor based on the offset.

[0072] like Figure 2 As shown, as one possible design for step S0, the offset between the rotary transformer and the Hall sensor during signal detection is obtained, and phase correction is performed on the rotary transformer or the Hall sensor based on the offset, including:

[0073] Step S01a. Obtain the first offset between the estimated position of the rotary transformer and the detected position of the Hall sensor at the moment of commutation of the permanent magnet motor;

[0074] It should be noted that, due to the weighted information of the motor rotor position, the phase of both the resolver and the Hall sensor must be consistent. The main factors causing phase inconsistency include the transmission mechanism (e.g., reducer) and the phase lag of the resolver during signal detection. Therefore, an offset is introduced to correct the phase of the position detected by the selective angle measurement system. Considering that the spatial position of the permanent magnet motor commutation is fixed, the control system can calculate the offset of the estimated value of the resolver-encoder at the moment of commutation and use the offset to correct it, thereby eliminating the effect of phase lag.

[0075] Step S02a. Add the first offset to the estimated position of the rotary transformer to obtain the phase-corrected estimated position of the rotary transformer.

[0076] like Figure 3As shown, as another possible design for step S0, the offset between the rotary transformer and the Hall sensor is obtained during signal detection, and phase correction is performed on the rotary transformer or the Hall sensor based on the offset, including:

[0077] Step S01b. Obtain the second offset between the Hall sensor estimated position and the rotary transformer detection position when the rotary transformer detects a change in the motor output shaft angle;

[0078] It should be noted that, since the position of the Hall sensor signal across the entire range is obtained by adding the position measured by the rotary transformer as the offset to the position of the Hall sensor, the offset calculation function can be triggered when the output shaft angle detected by the rotary transformer angle measurement system changes, thereby obtaining the position information converted from the Hall sensor signal.

[0079] Step S02b. Add the second offset to the detected position of the rotary transformer to obtain the estimated position of the Hall sensor after phase correction.

[0080] Step S2. Use the lower M bits of the second position signal to perform weighted replacement on the lower M bits of the first position signal to obtain the synthesized motor weighted position signal, so as to achieve accurate positioning of the robot joint, where M < N.

[0081] like Figure 4 As shown, preferably, in one possible design of step S2, the lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, including:

[0082] Step S21a. Select the high four bits of the first rotor position signal as the reliable bits, and select the low eight bits of the second rotor position signal as the accurate bits. At this time, N = 12.

[0083] Step S21a. Replace the lower eight bits of the first rotor position signal with the lower eight bits of the second rotor position signal, and use the replaced first rotor position signal as the synthesized motor rotor weighted position signal.

[0084] It should be noted that the number of bits N of the first rotor position signal and the second rotor position signal in this embodiment can be adjusted according to the measurement accuracy requirements. For example, it can be set to 8 bits, 12 bits, 16 bits, etc. There is no limitation here. The more bits, the higher the measurement accuracy requirement of the sensor.

[0085] It should be noted that, considering the direct decomposition of the position signal source into low-frequency and high-frequency components, the position information measured by the Hall sensor can be used as detailed information to supplement and replace the overall position information estimated by the rotary transformer, thus completing information weighting. Since both variables are processed and stored in binary form in digital control systems, the position variable of the motor rotor is expressed as follows: Figure 4 As shown, in Figure 4 In this example, the rotor position resolution estimated using a certain type of rotary transformer is 21.6°. It's understandable that using other types of rotary transformers would yield different estimated rotor position resolutions, which can be set according to requirements and are not limited here. In practice, the high four bits measured by the rotary transformer are the precise data. However, it's also understood that different high-order bits can be used when the signal bit length is different, such as three or five bits. In this embodiment, the high four bits of the first rotor position signal are used as reliable bits to determine a portion of the rotor weighted signal. Then, the lower eight bits of the first rotor position signal are weighted and replaced with the lower eight bits of the second rotor position signal as a supplement, resulting in the complete weighted rotor position signal.

[0086] like Figure 5 As shown, in a preferred embodiment of step S2, in another possible design, the lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized weighted position signal of the motor, including:

[0087] Step S21b. Select the high eleven bits of the first output shaft position signal as the reliable bits, and at the same time select the low five bits of the second output shaft position signal as the precise bits. At this time, N = 16.

[0088] Step S22b. Replace the lower five bits of the first output shaft position signal with the lower five bits of the second output shaft position signal, and use the replaced first output shaft position signal as the synthesized weighted position signal of the motor output shaft.

[0089] It should be noted that, since the output shaft position range calculated from the Hall sensor signal is limited, it can only serve as supplementary information for the output shaft detection. Therefore, the first output shaft position signal is taken as the high eleven bits, while only the low five bits of the first output shaft position signal are weighted and replaced with the low five bits of the second output shaft position signal to ensure the accuracy of the synthesized information. In practice, the high eleven bits measured by the rotary transformer are precise data. Of course, it can be understood that different high-bit data can be taken when the number of signal bits is different, such as the high ten bits, high nine bits, etc., which is not limited here. In this embodiment, the high eleven bits of the first output shaft position signal are used as reliable bits to determine part of the data of the weighted output shaft signal. Then, the low five bits of the first output shaft position signal are weighted and replaced with the low five bits of the second output shaft position signal as supplementary information to obtain the complete weighted position signal of the motor output shaft.

[0090] It should be noted that in practical applications, the motor position can be recalibrated by combining the weighted position signal of the motor rotor and the weighted position signal of the motor output shaft, thereby further ensuring the accuracy of robot positioning.

[0091] In one possible design, to overcome carry errors caused during signal synthesis and ensure the accuracy of the synthesized motor weighted position signal, the following additional steps are also included:

[0092] Step S3. Set the corresponding error correction bits in the lower M bits of the first position signal and the second position signal respectively, and perform error correction on the weighted position signal of the motor according to the comparison result of the error correction bits.

[0093] For example, when correcting errors in the weighted position signal of a motor rotor, errors generated during measurement and estimation can lead to incorrect combinations, with carry-over issues having the greatest impact. Therefore, the sixth and seventh bits of the two position variables are defined as correction bits. When the error correction bit of the position information estimated by the Hall position sensor signal is 11, and the error correction bit of the position information returned by the resolver is 00, it indicates that the latter caused an incorrect carry-over in the 8th bit due to a large quantization range. Subtracting 1 from this bit ensures correct combination. Similarly, when the error correction bit of the resolver position signal is 11 and the error correction bit of the Hall position sensor position signal is 00, the 8th bit is incremented by 1. Furthermore, the error correction principle for the weighted position signal of the motor output shaft is the same as that for the weighted position signal of the motor rotor, and will not be elaborated here.

[0094] Based on the above-disclosed content, the position signals of the motor system are collected by a rotary transformer and a Hall sensor, and stored in binary form. Then, based on the accuracy of the measurement signals from the rotary transformer and the Hall sensor at each position in the N-bit binary number, the high-precision data from the Hall sensor is used to replace the less accurate data from the rotary transformer, resulting in a synthesized weighted position signal for the motor. This yields a precise motor position signal. Since the motor is the driving mechanism for the robot joints, precise positioning of the robot joints can be achieved simultaneously with precise motor positioning, thus overcoming the technical problem of insufficient robot joint positioning caused by the quantization error of the rotary transformer.

[0095] like Figure 6 As shown, as a verification example of this embodiment, the detection accuracy improvement method is verified by establishing a simulation model. The model includes the following three parts: (1) Data preprocessing: phase correction and position information supplementation are performed on the output shaft angle converted by the Hall position sensor; (2) Data weighting: different bits are extracted from the two sets of position information and synthesized; (3) Error correction part: according to the processing method in the error correction table, possible weighting errors are processed. The results are as follows Figure 6 Figure (a) shows the actual position of the output shaft, the output shaft position curve measured by the rotary transformer, and the composite position curve, represented by the actual position, the detected position, and the composite position, respectively; Figure (b) shows the corresponding error curve. Simulation results show that due to the limited quantization accuracy of the resolver angle measurement system, the output shaft position detected by the rotary transformer has the largest error, with a maximum absolute error of 0.09°; the output shaft position error obtained by the composite method is within 0.005°, showing the best detection effect except for a small number of composite errors. Therefore, this information weighting method can effectively improve the position detection capability of the motor system.

[0096] In a second aspect, the present invention provides a precise positioning device for a robot joint, comprising:

[0097] The signal acquisition module is used to acquire the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, and store the first position signal and the second position signal in the form of N-bit binary numbers respectively.

[0098] The signal weighting module is used to replace the lower M bits of the first position signal with the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, so as to achieve precise positioning of the robot joint, where M < N.

[0099] In one possible design, the device further includes:

[0100] The phase correction module is used to acquire the offset between the rotary transformer and the Hall sensor during signal detection, and to perform phase correction on the rotary transformer or Hall sensor based on the offset.

[0101] In one possible design, the device further includes:

[0102] The error correction module is used to set corresponding error correction bits in the lower M bits of the first position signal and the second position signal respectively, and to correct the motor weighted position signal according to the comparison result of the error correction bits.

[0103] In one possible design, the signal acquisition module is specifically used for:

[0104] The rotation angle signal of the motor output shaft measured by the rotary transformer is obtained, and the rotation angle signal is converted into the first rotor position signal;

[0105] Acquire the second rotor position signal of the motor rotor measured by the Hall sensor.

[0106] In one possible design, the signal acquisition module is specifically used for:

[0107] Acquire the first output shaft position signal of the motor output shaft measured by the rotary transformer;

[0108] The motor rotor position signal measured by the Hall sensor is acquired, and the electronic rotor position signal is converted into the second output shaft position signal.

[0109] In one possible design, the signal weighting module is specifically used for:

[0110] The high four bits of the first rotor position signal are selected as the reliable bits, and the low eight bits of the second rotor position signal are selected as the accurate bits. At this time, N=12.

[0111] The lower eight bits of the first rotor position signal are weighted and replaced with the lower eight bits of the second rotor position signal, and the replaced first rotor position signal is used as the synthesized weighted rotor position signal of the motor.

[0112] In one possible design, the signal weighting module is specifically used for:

[0113] The high eleven bits of the first output shaft position signal are selected as the reliable bits, and the low five bits of the second output shaft position signal are selected as the precise bits. At this time, N=16.

[0114] The lower five bits of the first output shaft position signal are weighted and replaced with the lower five bits of the second output shaft position signal, and the replaced first output shaft position signal is the synthesized weighted position signal of the motor output shaft.

[0115] In one possible design, the phase correction module is specifically used for:

[0116] At the moment of commutation of the permanent magnet motor, obtain the first offset between the estimated position of the rotary transformer and the detected position of the Hall sensor;

[0117] Adding the first offset to the estimated position of the rotary transformer yields the phase-corrected estimated position of the rotary transformer.

[0118] In one possible design, the phase correction module is specifically used for:

[0119] The second offset between the Hall sensor's estimated position and the rotary transformer's detected position is obtained when the rotary transformer detects a change in the motor output shaft angle.

[0120] Adding the second offset to the position detected by the rotary transformer yields the estimated position of the Hall sensor after phase correction.

[0121] The working process, working details and technical effects of the aforementioned device provided in the second aspect of this embodiment can be found in the method described in the first aspect or any possible design of the first aspect, and will not be repeated here.

[0122] Thirdly, the present invention provides a computer device comprising a memory, a processor, and a transceiver connected in sequence and communication, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute a precise positioning method for robot joints as described in any possible design of the first aspect.

[0123] Specifically, the memory may include, but is not limited to, Random-Access Memory (RAM), Read-Only Memory (ROM), Flash Memory, First-In-First-Out (FIFO) Memory, and / or First-In-Last-Out (FILO) Memory, etc.; the processor may not be limited to the STM32F105 series microprocessor; the transceiver may be, but is not limited to, a WiFi (Wireless Fidelity) wireless transceiver, a Bluetooth wireless transceiver, a GPRS (General Packet Radio Service) wireless transceiver, and / or a ZigBee (a low-power LAN protocol based on the IEEE 802.15.4 standard) wireless transceiver, etc. Furthermore, the computer device may also include, but is not limited to, a power module, a display screen, and other necessary components.

[0124] The working process, working details and technical effects of the aforementioned computer device provided in the third aspect of this embodiment can be found in the method described in the first aspect or any possible design of the first aspect, and will not be repeated here.

[0125] Fourthly, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, perform a precise positioning method for robot joints as described in any possible design of the first aspect.

[0126] The computer-readable storage medium refers to a carrier for storing data, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives and / or memory sticks, etc. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0127] The working process, working details and technical effects of the aforementioned computer-readable storage medium provided in the fourth aspect of this embodiment can be found in the method described in the first aspect or any possible design of the first aspect, and will not be repeated here.

[0128] Fifthly, the present invention provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform a precise positioning method for a robot joint as described in any possible design of the first aspect.

[0129] The working process, working details and technical effects of the aforementioned computer program product containing instructions provided in the fifth aspect of this embodiment can be found in the method described in the first aspect or any possible design of the first aspect, and will not be repeated here.

[0130] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for precise positioning of robot joints, characterized in that, include: The first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor are acquired, and the first position signal and the second position signal are stored in the form of N-bit binary numbers respectively. The lower M bits of the first position signal are weighted and replaced by the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, so as to achieve precise positioning of the robot joint, where M < N.

2. The precise positioning method for robot joints according to claim 1, characterized in that, Before acquiring the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, the process also includes: During signal detection, the offset between the rotary transformer and the Hall sensor is acquired, and the phase of the rotary transformer or the Hall sensor is corrected based on the offset.

3. The precise positioning method for robot joints according to claim 1 or 2, characterized in that, Also includes: The corresponding error correction bits are set in the lower M bits of the first position signal and the second position signal respectively, and the motor weighted position signal is corrected according to the comparison result of the error correction bits.

4. The precise positioning method for robot joints according to claim 1, characterized in that, Acquiring the first position signal of the permanent magnet motor from the rotary transformer and the second position signal of the permanent magnet motor from the Hall sensor includes: The rotation angle signal of the motor output shaft measured by the rotary transformer is obtained, and the rotation angle signal is converted into the first rotor position signal; Acquire the second rotor position signal of the motor rotor measured by the Hall sensor.

5. The precise positioning method for robot joints according to claim 1, characterized in that, Acquiring the first position signal of the permanent magnet motor from the rotary transformer and the second position signal of the permanent magnet motor from the Hall sensor includes: Acquire the first output shaft position signal of the motor output shaft measured by the rotary transformer; The motor rotor position signal measured by the Hall sensor is acquired, and the electronic rotor position signal is converted into the second output shaft position signal.

6. The precise positioning method for robot joints according to claim 4, characterized in that, The lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized weighted position signal of the motor, including: The high four bits of the first rotor position signal are selected as the reliable bits, and the low eight bits of the second rotor position signal are selected as the accurate bits. At this time, N=12. The lower eight bits of the first rotor position signal are weighted and replaced with the lower eight bits of the second rotor position signal, and the replaced first rotor position signal is used as the synthesized weighted rotor position signal of the motor.

7. The precise positioning method for robot joints according to claim 5, characterized in that, The lower M bits of the first position signal are weighted and replaced using the lower M bits of the second position signal to obtain the synthesized weighted position signal of the motor, including: The high eleven bits of the first output shaft position signal are selected as the reliable bits, and the low five bits of the second output shaft position signal are selected as the precise bits. At this time, N=16. The lower five bits of the first output shaft position signal are weighted and replaced with the lower five bits of the second output shaft position signal, and the replaced first output shaft position signal is the synthesized weighted position signal of the motor output shaft.

8. The precise positioning method for robot joints according to claim 2, characterized in that, During signal detection, the offset between the rotary transformer and the Hall sensor is acquired, and phase correction is performed on the rotary transformer or Hall sensor based on the offset, including: At the moment of commutation of the permanent magnet motor, obtain the first offset between the estimated position of the rotary transformer and the detected position of the Hall sensor; Adding the first offset to the estimated position of the rotary transformer yields the phase-corrected estimated position of the rotary transformer.

9. The precise positioning method for robot joints according to claim 2, characterized in that, During signal detection, the offset between the rotary transformer and the Hall sensor is acquired, and phase correction is performed on the rotary transformer or Hall sensor based on the offset, including: The second offset between the Hall sensor's estimated position and the rotary transformer's detected position is obtained when the rotary transformer detects a change in the motor output shaft angle. Adding the second offset to the position detected by the rotary transformer yields the estimated position of the Hall sensor after phase correction.

10. A precise positioning device for robot joints, characterized in that, include: The signal acquisition module is used to acquire the first position signal of the permanent magnet motor collected by the rotary transformer and the second position signal of the permanent magnet motor collected by the Hall sensor, and store the first position signal and the second position signal in the form of N-bit binary numbers respectively. The signal weighting module is used to replace the lower M bits of the first position signal with the lower M bits of the second position signal to obtain the synthesized motor weighted position signal, so as to achieve precise positioning of the robot joint, where M < N.

Images