Method and device for measuring return difference of gear transmission mechanism in motor driving system

Abstract

The invention provides a return difference measuring method and device of a gear transmission mechanism in a motor driving system. According to the return difference measurement method, the return difference measurement value is indirectly determined by identifying the critical point that the gear transmission mechanism starts to respond to the driving signal, the critical point marks that the gear transmission mechanism completes the change from the idle stroke state to the effective transmission state, and the return difference measurement value is calculated based on the position data before the critical point. The return difference measurement value is a comprehensive index which contains the comprehensive influence of the gear backlash, the elastic deformation of the transmission shaft and the static friction force and reflects the overall transmission performance of the system, so that the return difference measurement value which reflects the overall transmission performance of the system and is real and comprehensive is obtained through measurement according to the technical scheme of the invention. According to the method, the transmission lag characteristic of the system under the actual working condition can be represented more accurately, and a more reliable data basis is provided for subsequent high-precision motion control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical transmission, and in particular to a back-lash measurement method and device for a gear transmission mechanism in a motor driving system. BACKGROUND

[0002] In the field of high-precision control such as industrial automation, robots and precision instruments, a motor driving system combined by a motor and a gear transmission mechanism is often adopted. However, the inherent backlash of the gear transmission mechanism, the elastic deformation of the transmission components and the friction between the joint surfaces and other nonlinear factors will cause the output shaft to respond to the input command with a significant lag when the driving direction is changed, that is, the transmission back-lash.

[0003] This back-lash effect seriously restricts the positioning accuracy and dynamic tracking performance of the system, especially in the motion scene of frequent start-stop or reversal, the lag and displacement loss caused by it will directly translate into cumulative error, resulting in unstable operation of the equipment, reduced control accuracy, and even impact, vibration and noise.

[0004] The measurement methods for such back-lash generally rely on complex hardware motion schemes, such as directly monitoring the displacement lag of the output shaft under a specific driving mode through high-precision sensors. Although these methods are direct, they usually have limitations such as complicated measurement process, high dependence on hardware configuration, inconvenient operation and difficulty in integration into online detection, making it difficult to implement conveniently and efficiently in actual production and maintenance sites. SUMMARY

[0005] Therefore, the present application provides a back-lash measurement method and device for a gear transmission mechanism in a motor driving system, which can conveniently, quickly and accurately calculate the back-lash value of the gear transmission mechanism.

[0006] Specifically, the present application is realized by the following technical solutions: According to a first aspect of the embodiments of the present application, a back-lash measurement method for a gear transmission mechanism in a motor driving system is provided, comprising: starting from a preset initial value of a driving signal, gradually increasing the driving signal strength applied to the motor in the motor driving system, and collecting the position data fed back by an encoder coaxially arranged with the motor at each driving signal strength; determining the critical driving signal strength at which the gear transmission mechanism starts to respond to the driving signal based on the trend of the position data; and obtaining the back-lash measurement value of the gear transmission mechanism according to the total amount of change in the position data before the critical driving signal strength.

[0007] Optionally, determining the critical drive signal intensity at which the gear transmission mechanism begins to respond to the drive signal based on the changing trend of the position data includes: identifying the changing trend of the data point sequence contained in the position data for each drive signal intensity; and determining the drive signal intensity as the critical drive signal intensity when the data point sequence is first identified to meet the increasing change condition.

[0008] Optionally, the data point sequence is identified to satisfy the increasing change condition by the following steps: curve fitting is performed on the relationship between the data point sequence and its corresponding driving signal intensity to obtain a fitting curve; if the slope of the fitting curve is greater than the slope threshold, it is determined that the data point sequence satisfies the increasing change condition.

[0009] Optionally, the hysteresis measurement method further includes: determining a reference value of the drive signal required to bring the gear transmission mechanism into an effective motion state under the target load condition based on the system parameters of the motor drive system; and setting the initial value of the drive signal to be less than the reference value of the drive signal.

[0010] Optionally, obtaining the backlash measurement value of the gear transmission mechanism based on the total change of position data before the critical drive signal intensity includes: determining whether the critical drive signal intensity is greater than the drive signal reference value; and if the critical drive signal intensity is determined to be greater than the drive signal reference value, obtaining the backlash measurement value of the gear transmission mechanism based on the total change of position data before the critical drive signal intensity.

[0011] Optionally, based on the system parameters of the motor drive system, determining the reference value of the drive signal required to enable the gear transmission mechanism to enter an effective motion state under the target load condition includes: acquiring the system parameters of the motor drive system, the system parameters including motor model parameters and gear transmission model parameters; obtaining the correspondence between motor speed and drive signal according to the motor model parameters and gear transmission model parameters; acquiring the target linear speed corresponding to the target load condition, and determining the drive signal corresponding to the target linear speed as the drive signal reference value according to the correspondence between motor speed and drive signal.

[0012] According to a second aspect of the embodiments of this specification, a backlash measurement device for a gear transmission mechanism in a motor drive system is provided, comprising: a data acquisition unit, configured to, when the motor in the motor drive system is in a stationary state, gradually increase the intensity of the drive signal applied to the motor starting from a preset initial value, and at each drive signal intensity, acquire position data fed back by an encoder coaxially arranged with the motor; a data analysis unit, configured to determine, based on the changing trend of the position data, the critical drive signal intensity at which the gear transmission mechanism begins to respond to the drive signal; and a backlash calculation unit, configured to obtain a backlash measurement value of the gear transmission mechanism based on the total change of the position data before the critical drive signal intensity.

[0013] According to a third aspect of the embodiments of this specification, a control device for a motor drive system is provided, including a processor and a memory for storing processor-executable instructions; wherein the processor is configured to implement the method of the first aspect of the embodiments of this specification.

[0014] According to a fourth aspect of the embodiments of this specification, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method of the first aspect of the embodiments of this specification.

[0015] According to a fifth aspect of the embodiments of this specification, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the method of the first aspect of the embodiments of this specification.

[0016] In the technical solution of this application, the physical backlash of the gears is not measured directly. Instead, the backlash measurement value is indirectly determined by identifying the critical point at which the gear transmission mechanism begins to respond to the drive signal. This critical point marks the change of the gear transmission mechanism from the idle state to the effective transmission state. The backlash measurement value calculated based on the position data before this critical point is a comprehensive indicator that reflects the overall transmission performance of the system, including the combined effects of tooth backlash, elastic deformation of the transmission shaft, and static friction. Therefore, the backlash measurement value obtained by this technical solution is a true and comprehensive backlash measurement value that reflects the overall transmission performance of the system. It can more accurately characterize the transmission hysteresis characteristics of the system under actual working conditions, providing a more reliable data basis for subsequent high-precision motion control.

[0017] This technical solution does not require complex auxiliary measuring fixtures or additional precision sensors. It only utilizes the inherent motor and encoder of the motor drive system itself. Hysteresis measurement can be completed through a specific drive signal scanning and data analysis process. This frees hysteresis measurement from dependence on a professional laboratory environment and can be used as a convenient on-site testing method that can be quickly integrated into the daily maintenance process of equipment.

[0018] Furthermore, the entire measurement process is automatically completed by a preset algorithm, eliminating subjective errors introduced by relying on human experience. The measurement mechanism of this technical solution can ensure the repeatability of measurement results. Regardless of when, where, or by whom the same system is operated, consistent and reliable measurement data can be obtained, greatly improving the rigor and efficiency of the quality control process.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this specification and, together with the description, serve to explain the principles of this specification.

[0021] Figure 1 This is a flowchart illustrating a backlash measurement method for a gear transmission mechanism in a motor drive system according to an exemplary embodiment of this specification; Figure 2 This is a structural block diagram of a motor drive system illustrated in this specification according to an exemplary embodiment; Figure 3 This specification illustrates a fitting curve diagram of position data and a PWM signal according to an exemplary embodiment. Figure 4 This specification is a schematic diagram of a control device for a motor drive system according to an exemplary embodiment. Figure 5 This is a block diagram illustrating a backlash measuring device for a gear transmission mechanism in a motor drive system according to an exemplary embodiment. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application.

[0023] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0024] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0025] Currently, the main methods for measuring backlash in gear transmission mechanisms include the following categories: 1) Hardware-driven measurement method: This method involves driving a gear transmission mechanism to rotate in both directions using a motor. High-precision encoders, angle sensors, and other torque sensors are used to record the state changes of the output shaft of the gear transmission mechanism. The hysteresis measurement result is obtained by calculating the deviation value of the forward and reverse strokes. However, this method requires the construction of a complex hardware testing platform, such as a loading motor and torque sensors. The operation steps are cumbersome, making it difficult to achieve fast and convenient on-site measurement.

[0026] 2) Static loading measurement method: An external force is applied to the gear transmission mechanism manually or mechanically, and the displacement response of its output shaft is observed. This method relies on manual operation, has poor repeatability, and cannot simulate dynamic loads under actual working conditions, resulting in deviations between the measurement results and practical applications.

[0027] 3) Optical or image processing technology: This method uses a high-speed camera to capture the gear's motion trajectory and combines it with image processing algorithms to analyze backlash changes. However, this approach is costly, has strict requirements regarding the reflective properties of the gear surface and ambient lighting, and involves complex data processing, making it unsuitable for the rapid inspection needs of industrial sites.

[0028] 4) Empirical modeling and data-driven approach: Fitting backlash characteristic curves to historical data or establishing backlash prediction models using machine learning algorithms. This approach relies on a large amount of sample data and is highly sensitive to parameters of gear transmission mechanisms (e.g., backlash distribution, material elastic modulus), resulting in limited generalization ability.

[0029] To address the aforementioned issues, this specification provides a backlash measurement method that is free from complex hardware requirements, easy to operate, highly adaptable, and offers controllable measurement accuracy, thereby improving the efficiency and reliability of performance evaluation for gear transmission structures.

[0030] The embodiments described in this specification will now be described in detail.

[0031] This application provides a method for measuring the backlash of a gear transmission mechanism in a motor drive system. Figure 1This is a flowchart illustrating a backlash measurement method for a gear transmission mechanism in a motor drive system according to an exemplary embodiment of this specification, as shown below. Figure 1 As shown, the hysteresis measurement method 100 includes at least the following steps S110 to S130: Step S110: When the motor in the motor drive system is stationary, starting from a preset initial value of the drive signal, the intensity of the drive signal applied to the motor is gradually increased, and at each drive signal intensity, position data fed back by the encoder coaxially set with the motor is collected.

[0032] like Figure 2 As shown, the motor drive system includes a motor, a gear transmission mechanism, and a load. The motor is the power source of the system, and its types include DC brushed motors, DC brushless motors, or stepper motors. The motor receives drive signals from the controller, typically PWM (Pulse Width Modulation) signals, and converts them into output torque and rotational motion. The encoder is coaxially mounted with the motor, allowing it to directly measure the angular displacement of the motor rotor. Its output position data is sent to the controller or data processing unit in real time. The gear transmission mechanism is connected to the output shaft of the motor. This gear transmission mechanism contains at least one gear pair, and in actual systems, it is usually composed of multiple gear pairs connected in series. All the tooth backlash, torsional elastic deformation of the transmission shaft, and friction between gear meshing within the gear transmission mechanism constitute the physical source of the hysteresis to be measured in this embodiment. The load is connected to the final output shaft of the gear transmission mechanism and is the object to be driven by the system. The load can be a printer head support mechanism, a paper feed mechanism, or a moving part requiring precise positioning. Backlash in gear transmission mechanisms can cause inaccurate printhead positioning or paper feed errors, thus affecting print quality. By applying the backlash measurement method of this embodiment, this backlash can be easily quantified and compensated, ultimately improving the printer's printing accuracy. Of course, in other embodiments, the load can also be a joint of a robotic arm, a lead screw of a precision platform, a roller of a conveyor belt, or any end effector.

[0033] Before performing hysteresis measurement, it is necessary to ensure that the entire motor drive system is stationary to eliminate the influence of historical motion on the gear clearance distribution and to restore the static friction of the system to its maximum value. This will establish a unified and reliable reference starting point for hysteresis measurement and ensure the accuracy and repeatability of the measurement results.

[0034] In some embodiments, the initial value of the drive signal is set to a PWM value lower than the system startup torque to ensure that the measurement can fully cover the entire process from being unable to overcome static friction to just being able to start. If the initial value is set too high, it may directly skip part of the hysteresis elimination stage, resulting in inaccurate measurement results.

[0035] In some embodiments, the drive signal strength applied to the motor is gradually increased by a preset step size. The preset step size is configured to precisely capture the critical point at which the gear transmission mechanism enters an effective motion state. For example, the preset step size is configured as two PWM count values, which can be reasonably set by those skilled in the art.

[0036] In some embodiments, position data fed back by the encoder is acquired under each drive signal strength within a preset time window. This preset time window is, for example, a time window of 1 second, 2 seconds, or other durations, to obtain a sufficient number of data point sequences to form a statistically significant data sequence, so that subsequent steps can accurately identify the changing trend of the position data.

[0037] Step S120: Based on the changing trend of the position data, determine the critical drive signal strength at which the gear transmission mechanism begins to respond to the drive signal.

[0038] The moment when the gear transmission mechanism begins to respond to the drive signal refers to the critical moment when the gear transmission mechanism changes abruptly from an idle state to an effective transmission state.

[0039] In the idle state before response, the motor's rotational motion is completely absorbed by the static friction and backlash of the gear transmission mechanism. During this process, the motor will exhibit slow, intermittent creeping or jumping motions; for example, the motor rotates slightly, then gets stuck, and then rotates slightly again. Within a preset time window for each drive signal strength, the position data recorded by the encoder changes smoothly over time, while the position data in adjacent preset time windows shows a step-like change. In the idle state, the motor's rotational motion is not effectively and linearly transmitted to the output load of the gear transmission mechanism, and the output load of the gear transmission mechanism does not produce the expected motion.

[0040] In the effective transmission state after response, the torque generated by the drive signal has completely overcome the maximum static friction and eliminated all tooth backlash. From this instant onward, the motor can rotate continuously and smoothly, and the motor's rotation is linearly transmitted to the load. In the effective transmission state, within a preset time window for each drive signal intensity, the position data recorded by the encoder changes over time as a smooth, sloping line.

[0041] Before and after the critical point, the motor's rotational state changes from intermittent creeping or jumping to smooth continuous motion. This change in behavior is captured by the coaxial encoder and reflected in the recorded position data as a shift from an unstable to a stable continuous state. Based on this, this embodiment identifies the critical point of this characteristic transition through data analysis and determines the sum of the accumulated idle displacements of the motor before this critical point as the system's hysteresis measurement value.

[0042] Step S130: Based on the total change in position data before the critical drive signal intensity, obtain the backlash measurement value of the gear transmission mechanism.

[0043] like Figure 1 As shown in the backlash measurement method, the embodiment does not directly measure the physical clearance of the gears. Instead, it indirectly determines the backlash measurement value by identifying the critical point at which the gear transmission mechanism begins to respond to the drive signal. This critical point marks the completion of the gear transmission mechanism's transition from an idle state to an effective transmission state. The backlash measurement value calculated based on the position data before this critical point is a comprehensive indicator reflecting the overall transmission performance of the system, which includes the combined effects of tooth backlash, transmission shaft elastic deformation, and static friction. Therefore, the backlash measurement value obtained through this technical solution is a true and comprehensive reflection of the overall transmission performance of the system. It can more accurately characterize the transmission hysteresis characteristics of the system under actual working conditions, providing a more reliable data foundation for subsequent high-precision motion control.

[0044] The method in this embodiment does not require complex auxiliary measurement fixtures or additional precision sensors. It only uses the motor and encoder inherent in the motor drive system itself to complete the hysteresis measurement through a specific drive signal scanning and data analysis process. This allows the hysteresis measurement to break free from dependence on a professional laboratory environment and can be used as a convenient on-site testing method that can be quickly integrated into the daily maintenance process of the equipment.

[0045] Furthermore, the entire measurement process is automatically completed by a preset algorithm, eliminating subjective errors introduced by relying on human experience. The measurement mechanism of this technical solution can ensure the repeatability of measurement results. Regardless of when, where, or by whom the same system is operated, consistent and reliable measurement data can be obtained, greatly improving the rigor and efficiency of the quality control process.

[0046] In some embodiments, determining the critical drive signal intensity at which the gear transmission mechanism begins to respond to the drive signal based on the changing trend of the position data in step S120 includes: identifying the changing trend of the data point sequence contained in the position data for each drive signal intensity; and determining the drive signal intensity as the critical drive signal intensity when the data point sequence first satisfies the increasing change condition.

[0047] In this embodiment, "first time" refers to the first drive signal strength that meets the incremental change condition during the test process in which the drive signal strength gradually increases from the initial value, in order to ensure the accuracy of the hysteresis measurement.

[0048] The incremental change condition in this embodiment is used to identify the transition of a data sequence from an unstable state to a stable, continuous, linearly increasing state. A data sequence that meets the incremental change condition is represented by a smooth oblique line segment.

[0049] Therefore, in one example, the data point sequence is identified to satisfy the increasing change condition by the following steps: curve fitting is performed on the relationship between the data point sequence and its corresponding driving signal intensity to obtain a fitted curve; if the slope of the fitted curve is greater than a slope threshold, it is determined that the data point sequence satisfies the increasing change condition. This slope threshold can be set empirically.

[0050] In some embodiments, method 100 further includes: determining a reference value of a drive signal required to bring the gear transmission mechanism into an effective motion state under a target load condition based on system parameters of the motor drive system; and setting the initial value of the drive signal to be less than the reference value of the drive signal.

[0051] The target load condition refers to the maximum working load that the system is expected to withstand in actual applications. Under no-load or light-load conditions, the driving force required for the gear transmission mechanism to enter effective motion is small, only needing to overcome the frictional force inside the gearbox. The drive signal reference value calculated based on this will be significantly low. If the initial drive signal value is set based on this, it may result in an excessively high initial value, failing to fully capture the hysteresis process under actual load. Therefore, this embodiment calculates the drive signal reference value under the target load condition.

[0052] The effective motion state refers to the working state in which the final output end of the gear transmission mechanism has established a stable and instantaneous linear transmission relationship with the motor. When the gear transmission mechanism is in the effective motion state, the backlash of all gear pairs has been eliminated. At the instant the gear transmission mechanism enters the effective motion state, there is a definite, continuous, and linear relationship between the rotation of the motor and the movement of the load, conforming to the transmission ratio. The motor rotates stably, and the load moves at a uniform speed accordingly. The opposite of the effective motion state is the ineffective motion state or idle state. In this state, the motor is in an intermittent creeping or jumping state, and its kinetic energy is used for elastic deformation and filling the backlash; the load does not produce effective, corresponding movement.

[0053] By setting the initial value of the drive signal to be less than the reference value of the drive signal, it is ensured that the encoder can completely record the position data during the hysteresis elimination stage, providing data support for accurately calculating the hysteresis measurement value, and avoiding unnecessary scanning in the invalid low signal range caused by starting from zero, thus saving computing resources.

[0054] In some embodiments, obtaining the backlash measurement value of the gear transmission mechanism based on the total change in position data before the critical drive signal intensity in step S130 includes: determining whether the critical drive signal intensity is greater than the drive signal reference value; and if the critical drive signal intensity is determined to be greater than the drive signal reference value, obtaining the backlash measurement value of the gear transmission mechanism based on the total change in position data before the critical drive signal intensity. This embodiment provides a validity verification mechanism for the backlash measurement value, ensuring the reliability and physical rationality of the final measurement result.

[0055] In some embodiments, determining the reference value of the drive signal required to enable the gear transmission mechanism to enter an effective motion state under a target load condition based on the system parameters of the motor drive system includes: acquiring the system parameters of the motor drive system, the system parameters including motor model parameters and gear transmission model parameters; obtaining the correspondence between motor speed and drive signal based on the motor model parameters and gear transmission model parameters; acquiring the target linear speed corresponding to the target load condition, and determining the drive signal corresponding to the target linear speed as the drive signal reference value based on the correspondence between motor speed and drive signal.

[0056] The gear transmission model parameters include, for example, one or more of the following parameters: Number of input gears and output gears; Gear ratio, which represents the ratio of the number of teeth on the output gear to the number of teeth on the input gear, affects the output speed and torque; Pressure angle, the inclination angle of the gear tooth surface, affects the strength and transmission efficiency of the gear; The input and output modules, specifically the module of a gear, determine its size. Input and output pitch circle radius, used to calculate the geometric parameters of the gear; Shaft diameter, indicating the diameter of the gear or shaft; The coefficient of friction represents the coefficient of frictional resistance in the gear transmission process; The meshing angle is the angle at which gears mesh.

[0057] The motor model parameters also include motor voltage, torque constant, back electromotive force constant, internal resistance, and other parameters.

[0058] Based on the motor model parameters and gear transmission model parameters mentioned above, the correspondence between motor speed and drive signal can be calculated. The target linear speed (Inches Per Second, IPS) corresponding to the target load condition of the equipment is a known value that can be obtained from the product manual. Based on the above correspondence, the PWM value corresponding to the IPS value can be calculated, thereby obtaining the drive signal reference value.

[0059] like Figure 3 As shown, after obtaining the drive signal reference value, the controller can configure the initial PWM value, for example... Figure 3 The PWM count value shown is 2. Starting from 2, the count is gradually increased until it reaches a value greater than the reference value of the drive signal, resulting in the following... Figure 3 The curve showing the relationship between the PWM count value and the corresponding motor position shows that when the PWM count value is 14, the position data presents a smooth sloping line, indicating that the PWM signal has reached the limit of overcoming gear hysteresis. At this point, the hysteresis of the gear transmission mechanism has been overcome, and the load output end of the gear transmission mechanism begins to enter an effective motion state. Therefore, the total distance the motor moves when the PWM count value is less than 14 is the hysteresis measurement value.

[0060] Figure 4 This is a schematic diagram of a control device for a motor drive system according to an exemplary embodiment of this specification. Please refer to... Figure 4 At the hardware level, the device includes a processor 402, an internal bus 404, a network interface 406, memory 408, a hardware acceleration device 410, and non-volatile memory 412, and may also include other hardware required for its functions. One or more embodiments of this application can be implemented in software, for example, the processor 402 reads the corresponding computer program from the non-volatile memory 412 into memory 408 and then runs it. Of course, in addition to software implementation, one or more embodiments of this application do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the above processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0061] Corresponding to the embodiments of the above-described hysteresis measurement method, this application also provides corresponding apparatus embodiments. Please refer to... Figure 5 The hysteresis measurement device can be specifically applied to, for example... Figure 4 The control device shown implements the technical solution of this application. The hysteresis measurement device includes: a data acquisition unit 510, a data analysis unit 520, and a hysteresis calculation unit 530, wherein: The data acquisition unit 510 is used to, when the motor in the motor drive system is stationary, gradually increase the intensity of the drive signal applied to the motor starting from a preset initial value, and at each drive signal intensity, acquire position data fed back by an encoder coaxially arranged with the motor. Data analysis unit 520 is used to determine the critical drive signal strength at which the gear transmission mechanism begins to respond to the drive signal based on the changing trend of the position data; The backlash calculation unit 530 is used to obtain the backlash measurement value of the gear transmission mechanism based on the total change of position data before the critical drive signal intensity.

[0062] In some embodiments, the data analysis unit 520 is configured to identify the changing trend of the data point sequence contained in the location data collected at each driving signal intensity; and when the data point sequence is first identified to meet the increasing change condition, the driving signal intensity is determined as the critical driving signal intensity.

[0063] In some embodiments, the data analysis unit 520 is used to perform curve fitting on the relationship between the data point sequence and its corresponding driving signal intensity to obtain a fitted curve; if the slope of the fitted curve is greater than a slope threshold, it is determined that the data point sequence satisfies the condition of incremental change.

[0064] In some embodiments, the hysteresis measuring device further includes a numerical reference unit, used to determine, based on the system parameters of the motor drive system, the drive signal reference value required to bring the gear transmission mechanism into an effective motion state under the target load condition; and to set the initial value of the drive signal to be less than the drive signal reference value.

[0065] In some embodiments, the backlash calculation unit 530 is further configured to determine whether the critical drive signal strength is greater than the drive signal reference value; if the critical drive signal strength is determined to be greater than the drive signal reference value, the backlash measurement value of the gear transmission mechanism is obtained based on the total change of position data before the critical drive signal strength.

[0066] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this application according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0067] Accordingly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any of the above embodiments.

[0068] Accordingly, embodiments of this application also provide a computer program product configured to perform the methods described in any of the above embodiments.

[0069] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0070] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0071] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0072] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0073] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0074] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for measuring the backlash of a gear transmission mechanism in a motor drive system, characterized in that, include: When the motor in the motor drive system is stationary, starting from a preset initial value of the drive signal, the intensity of the drive signal applied to the motor is gradually increased, and at each drive signal intensity, position data fed back by an encoder coaxially set with the motor is collected; Based on the changing trend of the position data, the critical drive signal strength at which the gear transmission mechanism begins to respond to the drive signal is determined; The backlash measurement value of the gear transmission mechanism is obtained based on the total change in position data before the critical drive signal strength.

2. The method according to claim 1, characterized in that, Determining the critical drive signal strength at which the gear transmission mechanism begins to respond to the drive signal based on the changing trend of the position data includes: For the location data collected under each driving signal strength, identify the changing trend of the data point sequence contained in the location data; When the data point sequence is first identified as satisfying the increasing change condition, the driving signal strength is determined as the critical driving signal strength.

3. The method according to claim 2, characterized in that, The following steps are used to identify whether the data point sequence satisfies the increasing change condition: The relationship between the data point sequence and its corresponding driving signal intensity is fitted to obtain a fitted curve. If the slope of the fitted curve is greater than the slope threshold, it is determined that the sequence of data points satisfies the condition of increasing change.

4. The method according to claim 1, characterized in that, Also includes: Based on the system parameters of the motor drive system, determine the reference value of the drive signal required to enable the gear transmission mechanism to enter an effective motion state under the target load condition. The initial value of the drive signal is set to be less than the reference value of the drive signal.

5. The method according to claim 4, characterized in that, The step of obtaining the backlash measurement value of the gear transmission mechanism based on the total change in position data before the critical drive signal strength includes: Determine whether the critical drive signal strength is greater than the drive signal reference value; If the critical drive signal strength is determined to be greater than the drive signal reference value, the backlash measurement value of the gear transmission mechanism is obtained based on the total change of position data before the critical drive signal strength.

6. The method according to claim 4, characterized in that, The system parameters based on the motor drive system determine the reference values ​​of the drive signal required to bring the gear transmission mechanism into an effective motion state under the target load condition, including: Obtain the system parameters of the motor drive system, including motor model parameters and gear transmission model parameters; Based on the motor model parameters and gear transmission model parameters, the correspondence between motor speed and drive signal is obtained; Obtain the target linear speed corresponding to the target load condition, and determine the drive signal corresponding to the target linear speed as the drive signal reference value based on the correspondence between the motor speed and the drive signal.

7. A backlash measuring device for a gear transmission mechanism in a motor drive system, characterized in that, include: The data acquisition unit is used to, when the motor in the motor drive system is stationary, start from a preset initial value of the drive signal, gradually increase the intensity of the drive signal applied to the motor, and at each drive signal intensity, acquire position data fed back by an encoder coaxially arranged with the motor. The data analysis unit is used to determine the critical drive signal strength at which the gear transmission mechanism begins to respond to the drive signal based on the changing trend of the position data. The backlash calculation unit is used to obtain the backlash measurement value of the gear transmission mechanism based on the total change of position data before the critical drive signal strength.

8. A control device for a motor drive system, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to implement the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

10. 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 method as described in any one of claims 1 to 6.

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