A compensation control system based on a high-precision planetary reducer

Abstract

This invention relates to the field of motor control technology and discloses a compensation control system based on a high-precision planetary reducer, including a motor, a planetary reducer, a motor-side encoder, a load-side encoder, and a servo driver. The invention constructs a threshold mapping array through the servo driver and, combining position deviation and envelope characteristic values, divides the transmission state into backlash-through state, elastic loading state, and rigid transmission state. The servo driver executes command redirection logic according to the transmission state, calculating and changing the final quadrature-axis reference current signal. By combining angular position matching judgment parameters, the invention pauses the integral term update in the backlash-through state and generates a current signal based on the boundary energy release current and damping attenuation coefficient. This prevents position deviation from accumulating in the idling range and causing integral saturation, reduces mechanical impact during gear re-meshing, and improves the position following accuracy of the servo system.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, specifically to a compensation control system based on a high-precision planetary reducer. Background Technology

[0002] Planetary gear reducers have eccentric deviations during manufacturing, causing the system to exhibit periodic backlash and elastic deformation errors related to the rotation angle during operation. Existing control methods, when using fixed thresholds for state determination, cannot adapt to the changes in mechanical errors under different rotation angles, resulting in deviations in the control system's identification of the determination boundaries.

[0003] During the process of driving a planetary gear reducer by a motor, it is difficult for the system to clearly distinguish between the idle and backlash stages of the transmission chain and the torsional stage. When the transmission system is in the backlash range, the integral term of the speed loop inside the control system continuously accumulates, causing integral saturation. When the gears finish idling and re-engage, the accumulated current command will cause the motor to output excessive electromagnetic torque instantaneously, resulting in mechanical impact.

[0004] Furthermore, the control system relies on direct differential calculation of the position acquisition signal when acquiring speed feedback data. Direct differential operation amplifies the quantization noise of the position sensor. The sampling time difference between the time-sharing data from the motor side and the load side causes phase misalignment in the speed data, reducing the overall control accuracy of the system.

[0005] Therefore, this invention proposes a compensation control system based on a high-precision planetary reducer to overcome the shortcomings of the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a compensation control system based on a high-precision planetary reducer. This system solves the problems caused by backlash error, eccentricity error, and elastic deformation error generated by machining eccentricity deviation within the planetary reducer. Conventional control modes cannot distinguish between the idle clearance stage and the torsional stage of the mechanical system, which leads to increased speed tracking error and mechanical impact force generated at the moment of gear re-meshing.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a compensation control system based on a high-precision planetary reducer, comprising a motor, a planetary reducer, a motor-side encoder, a load-side encoder, and a servo driver. The output shaft of the motor is connected to the input end of the planetary reducer, which has an output end. The load-side encoder is mounted on the output end of the planetary reducer, and the motor-side encoder is mounted on the rotor end of the motor. The servo driver is connected to the motor, the motor-side encoder, and the load-side encoder, respectively.

[0009] The servo driver has a set control clock cycle and internally operates speed loop proportional-integral control and low-level current loop control. The servo driver calculates the position deviation based on the motor-side and load-side position signals, and generates the original quadrature-axis reference current signal using speed loop proportional-integral control. The servo driver constructs a threshold mapping array in a non-volatile memory area, storing the backlash detection critical threshold and rigid transmission judgment margin within the array. The servo driver combines the position deviation, backlash detection critical threshold, and rigid transmission judgment margin to classify the transmission state into backlash crossing state, elastic loading state, and rigid transmission state. Based on the transmission state, the servo driver executes instruction redirection logic and modifies the original quadrature-axis reference current signal to obtain the final quadrature-axis reference current signal, which is then transmitted to the motor.

[0010] The servo driver extracts the characteristic tooth count of the planetary reducer and uses this count to calculate the spatial period. The servo driver discretizes the spatial period, reads the discrete resolution parameter, and combines the discrete resolution parameter and the spatial period to calculate the total number of discrete nodes. Based on the total number of discrete nodes, the servo driver allocates a contiguous memory address space within the non-volatile memory area, establishing this contiguous address space as a threshold mapping array. The servo driver acquires the mechanical system's baseline response test data, controls the motor to perform forward, reverse, and loaded operation, and simultaneously records the feedback signals from the motor-side encoder and the load-side encoder. The servo driver extracts backlash width data and elastic deformation data, generating a backlash judgment threshold based on the backlash width data and a rigid transmission judgment margin based on the elastic deformation data.

[0011] The servo driver has a dedicated random access memory (RAM) area. An internal hardware timer generates a synchronization trigger signal, which is sent to the motor-side encoder and the load-side encoder via a communication bus. The servo driver reads the absolute angle data latched in the motor-side and load-side encoders, converting the angle values ​​into motor-side and load-side position signals, respectively. The servo driver stores these signals in the RAM. The servo driver reads the rated reduction ratio parameter of the planetary gearbox, calculates the motor-side position signal based on this parameter, and calculates the position deviation by subtracting the calculated motor-side and load-side position signals. The servo driver internally runs a discrete state observer to process the motor-side and load-side position signals. It extracts speed information using the state convergence characteristics of the discrete state observer, directly deriving the speed state quantity, and scaling it to convert it into smoothed angular velocities for the motor and load sides.

[0012] The servo driver performs a multiplicative envelope operation based on the absolute value of the position deviation, the smoothed angular velocity of the motor, the smoothed angular velocity on the load side, the backlash detection threshold, and the rigid transmission detection margin to generate position envelope feature values, backlash envelope boundary values, and rigid transmission boundary values. The servo driver then compares the position envelope feature values ​​and backlash envelope boundary values ​​with the rigid transmission boundary values, and classifies the transmission state into backlash crossing state, elastic loading state, and rigid transmission state based on the comparison results.

[0013] The servo driver reads the historical drive state from the previous control clock cycle stored in the historical state register and performs a logical comparison with the current drive state determined in the current control clock cycle. The servo driver triggers the transition flag when the historical drive state from the previous control clock cycle is a non-backlash crossing state and the current drive state in the current control clock cycle is a backlash crossing state. The servo driver extracts the original quadrature-axis reference current signal from the current control loop and latches it as a boundary release current based on the transition flag.

[0014] When the servo drive confirms that the transmission state is rigid, it triggers the pass-through operation branch in the command redirection logic. Under the pass-through operation branch, the servo drive maintains the original closed-loop control data stream, acquires the speed command, and calculates the speed deviation by subtracting the speed command from the smoothed angular velocity of the motor. Based on the speed deviation, the servo drive performs discretized proportional-integral (PI) mathematical calculations, executes speed loop PI control operations, and directly transmits the original quadrature-axis reference current signal as the final quadrature-axis reference current signal to the motor.

[0015] When the servo driver confirms that the transmission state is in an elastic loading state, it triggers the feedforward superposition operation branch in the command redirection logic. The servo driver reads the stiffness conversion coefficient and extracts the position deviation and the original quadrature-axis reference current signal generated by the speed loop proportional-integral control from the random access memory. Under the feedforward superposition operation branch, the servo driver couples the position deviation and the original quadrature-axis reference current signal for calculation, and calculates the deformation compensation current based on the position deviation and the stiffness conversion coefficient. The servo driver superimposes the deformation compensation current onto the original quadrature-axis reference current signal and transmits the final quadrature-axis reference current signal integrating the deformation compensation current to the motor.

[0016] When the servo driver confirms that the transmission state is backlash-through, it triggers the anti-saturation damping substitution branch in the command redirection logic. Under the anti-saturation damping substitution branch, the servo driver suspends the update of the speed loop integral term, keeping the integral term value of the previous control clock cycle unchanged. The servo driver reads the damping attenuation coefficient, generates the final quadrature-axis reference current signal under backlash-through state based on the boundary energy release current and the damping attenuation coefficient, and transmits the final quadrature-axis reference current signal to the motor.

[0017] This invention provides a compensation control system based on a high-precision planetary reducer. It has the following advantages:

[0018] 1. This invention constructs a threshold mapping array within a non-volatile memory area, combining the characteristic number of teeth and discretized spatial period of the planetary reducer to establish a correspondence between the backlash determination critical threshold and the rigid transmission determination margin and the specific angular position. The servo driver reads the determination parameters from the corresponding address node in the threshold mapping array according to the angle addressing index value, eliminating the interference of periodic errors caused by machining eccentricity deviation, and realizing control operation that matches the determination boundary according to the rotation angle position.

[0019] 2. This invention divides the transmission state into backlash crossing state, elastic loading state, and rigid transmission state by numerically comparing the position envelope feature value with the backlash envelope boundary value and the rigidity envelope boundary value, and executes command redirection logic in different transmission states. In the backlash crossing state, the servo driver suspends the update of the speed loop integral term and generates the final quadrature axis reference current signal based on the latched boundary energy release current and damping attenuation coefficient, preventing the position deviation from accumulating in the idle range and causing integral saturation, and reducing the mechanical impact when the gear end faces re-contact.

[0020] 3. This invention synchronously acquires the motor-side position signal and the load-side position signal through a hardware timer, and processes these signals using a discrete state observer. The discrete state observer generates the smooth angular velocity of the motor and the smooth angular velocity of the load side according to the state convergence characteristics, replacing the extraction step of directly performing differential calculations on the position deviation. This filters out quantization noise in the position acquisition channel and reduces data phase misalignment during the speed command calculation process. Attached Figure Description

[0021] Figure 1 This is a system block diagram of the present invention.

[0022] Figure 2 This is a flowchart of the method of the present invention.

[0023] Figure 3 This is the spatial distribution diagram of the threshold mapping array of the present invention.

[0024] Figure 4 This is a timing diagram of the transmission state transition and transition flag bit of the present invention.

[0025] Figure 5 This is a comparison chart of the position deviation under conventional PI control and control under the present invention.

[0026] Figure 6 This is a diagram showing the evolution of the cross-axis reference current signal under the backlash crossing state of this invention.

[0027] Figure 7 This is a comparison diagram of smooth angular velocity tracking on the motor side and load side of the present invention.

[0028] Figure 8 This is a comparison diagram of the gear meshing impact torque of the present invention. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] See attached document Figure 1 This invention provides a compensation control system based on a high-precision planetary reducer, including a motor, a planetary reducer, a motor-side encoder, a load-side encoder, and a servo driver. The output shaft of the motor is connected to the input end of the planetary reducer. The planetary reducer has an output end. The load-side encoder is installed at the output end of the planetary reducer. The motor-side encoder is installed at the rotor end of the motor. The servo driver is connected to the motor, the motor-side encoder, and the load-side encoder respectively.

[0031] The servo drive runs a field-oriented control algorithm and has a current loop control node. The servo drive receives the motor-side position signal from the motor-side encoder and the load-side position signal from the load-side encoder through the communication bus. The servo drive generates a quadrature-axis reference current signal based on the motor-side position signal and the load-side position signal. The servo drive outputs the quadrature-axis reference current signal to the motor and changes the output torque of the motor by adjusting the quadrature-axis reference current signal.

[0032] The servo driver is set with a control clock cycle. During the control clock cycle, the servo driver reads data from the motor-side encoder and the load-side encoder. The motor-side encoder and the load-side encoder maintain the synchronization of data sampling through a distributed clock mechanism. The servo driver is divided into a non-volatile memory area and a random access memory area. The non-volatile memory area is used to store threshold mapping array parameters, and the random access memory area is used to execute state observer operations and current command redirection logic during the control clock cycle.

[0033] See attached document Figure 2 Based on the aforementioned compensation control system based on a high-precision planetary reducer, this invention also provides a compensation control method based on a high-precision planetary reducer, which includes the following steps:

[0034] S10, the servo driver constructs a threshold mapping array in the non-volatile memory area, the servo driver extracts the characteristic number of teeth of the planetary reducer, the servo driver discretizes the spatial period corresponding to the characteristic number of teeth, and the servo driver stores the tooth backlash determination critical threshold and the rigid transmission determination margin into the threshold mapping array.

[0035] S20, the servo driver synchronously reads the motor-side position signal and the load-side position signal within the control clock cycle. The servo driver combines the motor-side position signal and the load-side position signal to calculate the position deviation. The servo driver runs the discrete state observer to process the motor-side position signal and the load-side position signal. The servo driver generates the smooth angular velocity of the motor and the smooth angular velocity of the load.

[0036] S30, the servo driver calls the backlash determination critical threshold and rigid transmission determination margin in the threshold mapping array according to the load side position signal. The servo driver combines the smooth angular velocity of the motor, the smooth angular velocity of the load side, the backlash determination critical threshold and the rigid transmission determination margin to perform a multiplication envelope operation. The servo driver divides the transmission state into backlash crossing state, elastic loading state and rigid transmission state according to the result of the multiplication envelope operation. When the transmission state changes from elastic loading state to backlash crossing state, the servo driver captures the cross-axis reference current signal. The servo driver stores the captured cross-axis reference current signal as the boundary release current in the random access memory area.

[0037] S40, the servo driver executes command redirection logic and changes the quadrature axis reference current signal according to the transmission state. Under rigid transmission dynamics, the servo driver maintains the speed loop proportional-integral control and the underlying current loop control. Under elastic loading state, the servo driver performs current feedforward compensation in combination with position deviation. Under backlash crossing state, the servo driver freezes the integral term and generates a discrete attenuation form of the quadrature axis reference current signal based on the boundary energy release current to replace the original speed loop output. Under backlash crossing state, the servo driver performs discrete damping energy release action in combination with the boundary energy release current. The servo driver transmits the finally generated quadrature axis reference current signal to the motor.

[0038] The specific steps of the compensation control method are explained in detail below.

[0039] Step S10 includes the following sub-steps:

[0040] S101, the servo driver acquires the characteristic number of teeth of the planetary reducer. The process of acquiring mechanical parameters by the servo driver can be accomplished by reading from a communication bus and writing parameters to a host computer, which is well-known in the field and will not be described further here.

[0041] The servo driver stores the received characteristic tooth count in a non-volatile memory area. There is a machining eccentricity deviation inside the planetary reducer. This deviation causes a non-uniform backlash distribution during rotation.

[0042] The characteristic tooth count is the equivalent tooth count used to characterize the repetition period of the internal meshing error of the planetary reducer. The equivalent tooth count is determined based on at least one mechanical parameter among the number of teeth on the sun gear, the number of teeth on the planet gears, the number of teeth on the internal gear ring, and the number of planet gears. The characteristic tooth count is used to determine the spatial period of the repetition of backlash error, eccentricity error, and elastic deformation error with respect to angle during the rotation of the output end of the planetary reducer.

[0043] When the error repetition period of a planetary reducer is determined by a single gear component, the characteristic number of teeth is taken as the number of teeth of that gear component; when the error repetition period is determined by multiple gear components, the characteristic number of teeth is taken as the equivalent number of teeth calculated from the meshing repetition period of each gear component.

[0044] For example, when the main periodic error of a planetary reducer originates from the meshing eccentricity between a single-stage planetary gear and the internal gear ring, the equivalent number of teeth can be obtained by converting the number of teeth of that stage of planetary gears with the transmission ratio. The specific mathematical conversion for parameter acquisition is a routine calculation in the field of mechanical transmission.

[0045] S102, the servo driver reads the number of characteristic teeth in the non-volatile memory area. The servo driver uses the number of characteristic teeth to calculate the space period. The servo driver performs the space period calculation process according to the following formula:

[0046] ;

[0047] In the formula, Indicates spatial period; Indicates the number of characteristic teeth; This represents the constant value of pi.

[0048] The spatial period represents the repeating angular span of the mechanical error characteristics within one revolution of the planetary gear reducer's output end. The servo driver writes the calculated spatial period back to the non-volatile memory area.

[0049] S103, the servo driver reads the discrete resolution parameter. The discrete resolution parameter represents the angle step size for meshing the rotation angle. The specific operation of the servo driver acquiring the parameter can be accomplished by a host computer or by writing to an external terminal; the parameter acquisition steps are well-known in the art and will not be described further here. The servo driver uses the discrete resolution parameter and the spatial period to calculate the total number of discrete nodes.

[0050] When the ratio of the spatial period to the discrete resolution parameter is not an integer, the servo driver performs an up-rounding operation on this ratio to ensure that the threshold mapping array can cover the complete spatial period. The total number of discrete nodes is determined by the following formula:

[0051] ;

[0052] In the formula, This represents the total number of discrete nodes; Indicates spatial period; Indicates discrete resolution parameters; This indicates a rounding up operation. The valid index range for the threshold mapping array is 0 to... .

[0053] S104, the servo driver addresses and allocates a contiguous memory address space within the non-volatile memory area based on the total number of discrete nodes. The servo driver establishes this contiguous memory address space as a threshold mapping array. The threshold mapping array presents a one-dimensional data structure. The servo driver assigns incremental discrete index values ​​to the memory addresses within the threshold mapping array in sequence. The servo driver associates the discrete index values ​​with specific angular intervals divided within the spatial period. The servo driver establishes a direct addressing relationship between the rotational angle position and the underlying hardware address of the non-volatile memory area through this one-dimensional data structure.

[0054] Each discrete index value in the threshold mapping array corresponds to an angle interval, and each angle interval stores at least the backlash determination critical threshold and the rigid transmission determination margin. The threshold mapping array... The data unit corresponding to each discrete index value is represented as follows:

[0055] ;

[0056] In the formula, Represents the threshold mapping array of the first... One data unit; Represents discrete index values; Indicates the first The critical threshold for tooth gap determination corresponding to each angle interval; Indicates the first Rigid transmission judgment margin corresponding to each angle interval; This represents the total number of discrete nodes.

[0057] For any discrete index value ,satisfy:

[0058] ;

[0059] In the formula, Indicates the first The critical threshold for tooth gap determination corresponding to each angle interval; Indicates the first Rigid transmission judgment margin corresponding to each angle interval; This represents a discrete index value.

[0060] S105, the servo drive acquires the baseline response test data of the mechanical system. For acquiring this data, the servo drive controls the motor to perform forward, reverse, and loaded operation under preset low-speed conditions, and simultaneously records the feedback signals from the motor-side encoder and the load-side encoder.

[0061] Among them, the backlash width data is obtained by low-load forward and reverse rotation tests under no-load or less than the preset small torque threshold; the elastic deformation data is obtained by tests under preset load torque, step torque or sweep frequency torque.

[0062] The servo driver calculates the relative deviation between the angular position of the motor-side position signal (after being converted to the output of the planetary reducer) and the load-side position signal within each discrete angular interval. It also extracts backlash width data based on the idle distance during forward / reverse switching and extracts elastic deformation data based on the deviation amount when the relative deviation stabilizes under applied torque. Both backlash width and elastic deformation data change periodically with the angular position of the planetary reducer output.

[0063] S106, the servo driver calibrates the backlash determination critical threshold and rigid transmission determination margin within each discrete angle interval based on the relative deviation between the angular position calculated from the motor-side position signal to the planetary reducer output and the load-side position signal.

[0064] The servo driver calculates the position deviation using the following formula:

[0065] ;

[0066] In the formula, Indicates the first Position deviation within one control clock cycle; Indicates the first Motor-side position signal within one control clock cycle; Indicates the rated reduction ratio parameter; Indicates the first The load-side position signal within each control clock cycle.

[0067] For the For each discrete angle interval, the servo driver uses the range of position deviation variation during forward and reverse low-load tests as backlash width data, and generates a critical threshold for backlash judgment based on this backlash width data and a preset safety margin. The servo driver uses the range of position deviation during the load test when it reaches a stable state as elastic deformation data, and generates a rigid transmission judgment margin based on this elastic deformation data and a preset rigidity margin. .

[0068] To ensure that the transmission state division has continuous intermediate intervals, the servo driver... and Perform size relationship verification. When ≤ At that time, the servo driver corrects the rigid transmission judgment margin according to the following formula:

[0069] ;

[0070] In the formula, Indicates the first Rigid transmission judgment margin corresponding to each angle interval; Indicates the first The critical threshold for tooth gap determination corresponding to each angle interval; This indicates the preset minimum elastic loading range width; This represents a discrete index value.

[0071] The backlash threshold is used to define the critical boundary line when the internal gears of the planetary reducer disengage from each other and are in a free-running state; the rigid transmission margin is used to define the critical boundary line when the internal gears of the planetary reducer finish the main torsional deformation process and enter the rigid transmission state.

[0072] S107, the servo driver aligns a specific angle range with discrete index values ​​in the threshold mapping array. The servo driver extracts numerical parameters that match the specific angle range from the backlash determination critical threshold and rigid transmission determination margin. The servo driver writes the matched backlash determination critical threshold and rigid transmission determination margin into the non-volatile memory address pointed to by the discrete index value in the threshold mapping array. The servo driver iterates through all discrete index values ​​sequentially. The servo driver completes the data persistence operation of the backlash determination critical threshold and rigid transmission determination margin in the non-volatile memory area. The threshold mapping array has the data addressing capability to independently output determination parameters for different rotation angles.

[0073] Step S20 includes the following sub-steps:

[0074] S201, the servo driver uses an internal hardware timer to generate a synchronization trigger signal. The control clock cycle represents the time interval for the servo driver to perform low-level current calculations. The servo driver issues a synchronization trigger signal at the beginning of the control clock cycle. The setting operation for the hardware timer to generate the interrupt signal can be accomplished by writing microcontroller register code by those skilled in the art; the low-level interrupt execution steps are well-known in the field and will not be described further here.

[0075] S202, the servo drive sends a synchronous trigger signal to the motor-side encoder and the load-side encoder via the communication bus. The motor-side encoder and the load-side encoder latch their internal absolute angle data at the same moment they receive the synchronous trigger signal. The servo drive utilizes a distributed clock mechanism to eliminate the time deviation between the arrival of the synchronous trigger signal and the arrival of the synchronous trigger signal at the motor-side encoder and the load-side encoder.

[0076] The communication bus is an industrial communication bus that supports distributed clock synchronization. Both the motor-side encoder and the load-side encoder have synchronous latching functions. Synchronous latching functions include latching based on hardware trigger signals or synchronous sampling based on distributed clock timestamps. The servo driver uses this synchronous latching function to ensure that the motor-side position signal and the load-side position signal correspond to sampling times within the same control clock cycle.

[0077] The data transmission and reception process of the communication bus can be completed by those skilled in the art in conjunction with the industrial Ethernet protocol. The communication bus transmission method is a well-known technology in this field and will not be described in detail here.

[0078] S203, the servo driver reads the absolute angle data latched in the motor-side encoder and the load-side encoder. The servo driver converts the read angle values ​​into motor-side position signals and load-side position signals, respectively. The servo driver stores the motor-side position signals and load-side position signals in the random access memory. The motor-side position signals and load-side position signals have the same timestamp attribute. The servo driver uses synchronous acquisition to eliminate the data phase misalignment caused by time-division sampling.

[0079] S204, the servo driver reads the rated reduction ratio parameter of the planetary reducer from the non-volatile memory area. The rated reduction ratio parameter represents the ratio of the rotational speeds at the input and output ends of the planetary reducer under ideal rigid transmission conditions. The process of the servo driver accessing conventional mechanical parameters can be accomplished by writing low-level memory read / write code by those skilled in the art; the data access steps are well-known in the field and will not be described further here.

[0080] The S205 servo driver uses the rated reduction ratio parameter to calculate the motor-side position signal. The servo driver then subtracts the calculated motor-side position signal from the load-side position signal. The servo driver calculates the position deviation.

[0081] S206, Position deviation eliminates the normal speed reduction and torque increase effect of the planetary reducer. Position deviation directly reflects the mechanical backlash angle and gear torsional angle within the planetary reducer. The servo driver stores the position deviation in random access memory. The servo driver uses the position deviation as the data source for calculating subsequent state compensation actions.

[0082] S207, the servo driver introduces the motor-side position signal and the load-side position signal into an internally running discrete state observer. The servo driver internally constructs this discrete state observer based on a dual-inertia elastic transmission physical model that includes the motor's moment of inertia, the load's moment of inertia, and the equivalent stiffness of the drive shaft. The observation inputs of the discrete state observer include the motor-side position signal and the load-side position signal, which are referred to the output of the planetary gearbox. The state variables of the discrete state observer include at least the motor-side reduced angular position, the motor-side smoothed angular velocity, the load-side angular position, and the load-side smoothed angular velocity.

[0083] The state variables of a discrete state observer are represented as follows:

[0084] ;

[0085] In the formula, Indicates the first Discrete state observer state variables within a control clock cycle; Indicates the first The estimated angular position on the motor side of the planetary reducer output terminal within one control clock cycle; Indicates the first Smooth motor angular velocity within one control clock cycle; Indicates the first Estimated angular position on the load side within one control clock cycle; Indicates the first The load-side smooth angular velocity is controlled within one clock cycle.

[0086] The observations of the discrete state observer are represented as follows:

[0087] ;

[0088] In the formula, Indicates the first Observations within a control clock cycle; Indicates the first Motor-side position signal within one control clock cycle; Indicates the rated reduction ratio parameter; Indicates the first The load-side position signal within each control clock cycle.

[0089] The discrete-state observer performs prediction and correction operations according to the following formula:

[0090] ;

[0091] In the formula, Indicates the first Discrete state observer state variables within a control clock cycle; Represents the discrete state transition matrix; Indicates the first Discrete state observer state variables within a control clock cycle; Represents a discrete input matrix; Indicates the first The electromagnetic torque input quantity calculated from the quadrature axis reference current signal within one control clock cycle; This represents the observer feedback gain matrix; Indicates the first Observations within a control clock cycle; This represents the observation matrix.

[0092] In S208, the servo driver uses a discrete state observer to compare the input motor-side and load-side position signals with the predicted positions generated by the discrete dynamics model. The servo driver then corrects the internal state variables of the discrete dynamics model based on the comparison results. The servo driver extracts velocity information using the state convergence characteristics of the discrete state observer. The servo driver uses discrete state observer operations instead of direct differential operations on the position signals. Direct differential operations amplify quantization noise in the system's acquisition channels and cause phase lag in the velocity signals.

[0093] S209, the servo driver directly derives the velocity state variables from the internal state variables of the corrected discrete state observer. The servo driver scales the velocity state variables to convert them into smoothed motor angular velocities and load-side smoothed angular velocities. The smoothed motor angular velocity represents the motor rotational speed filtered out for quantization noise and referred to the planetary gearbox output according to the rated reduction ratio parameters. The smoothed load-side angular velocity represents the planetary gearbox output rotational speed after filtering out quantization noise. The servo driver stores the smoothed motor angular velocities and load-side smoothed angular velocities in random access memory. The smoothed motor angular velocities and load-side smoothed angular velocities provide transient speed tracking data with lower noise and smaller phase lag compared to direct differential operations.

[0094] Step S30 includes the following sub-steps:

[0095] S301, the servo driver reads the load-side position signal from the random access memory. The servo driver reads the spatial period and discrete resolution parameters from the non-volatile memory. The servo driver performs a modulo-normalization operation on the load-side position signal using the spatial period. The modulo-normalization operation is used to extract the relative position of the load-side position signal within a single spatial period and is used to handle cases where the load-side position signal is negative or has multiple loops. The servo driver calculates the normalized relative position according to the following formula:

[0096] ;

[0097] In the formula, Indicates the first Relative position within each control clock cycle; Indicates the first The load-side position signal within each control clock cycle; Indicates spatial period; This indicates the modulo operation.

[0098] The servo driver divides the relative position by the discrete resolution parameter and rounds it down, then applies boundary constraints to the index value to generate the addressing index value within the control clock cycle:

[0099] ;

[0100] In the formula, Indicates the first The address index value within each control clock cycle; This represents the total number of discrete nodes; Indicates the first Relative position within each control clock cycle; Indicates discrete resolution parameters; This indicates the floor function; This indicates the minimum value operation; This indicates the operation of finding the maximum value.

[0101] In step S302, the servo driver converts the address index value into a memory offset. For microcontrollers performing memory offset addressing and data reading operations, those skilled in the art can use pointer access or array subscript indexing to write program code to accomplish this. The memory addressing and reading steps are well-known techniques in the field and will not be described further here. The servo driver uses the memory offset to locate a specific address node in the threshold mapping array within the non-volatile memory area.

[0102] S303, the servo driver extracts the backlash determination critical threshold and rigid transmission determination margin stored in a specific address node. The servo driver writes the extracted backlash determination critical threshold and rigid transmission determination margin into the random access memory area. The servo driver uses an addressing read mechanism to introduce the error boundary parameters corresponding to the current position into the control clock cycle. The servo driver prepares the basic data conditions for subsequent multiplication envelope operations.

[0103] S304, the servo driver reads the position deviation, motor smooth angular velocity and load-side smooth angular velocity from the random access memory area, and extracts the position deviation, motor smooth angular velocity and load-side smooth angular velocity as the basic data for state calculation.

[0104] The S305 servo driver performs a multiplicative envelope calculation using the absolute value of the position deviation, the smoothed angular velocity of the motor, the smoothed angular velocity on the load side, the backlash detection threshold, and the rigid transmission detection margin. To prevent the envelope boundary from approaching zero at zero speed, low speed, start-stop, or commutation, the servo driver sets a minimum speed protection value. The speed envelope coefficient is determined according to the following formula:

[0105] ;

[0106] In the formula, Indicates the first The speed envelope coefficient within each control clock cycle; Indicates the first Smooth motor angular velocity within one control clock cycle; Indicates the first Smooth angular velocity on the load side within each control clock cycle; This indicates the preset minimum speed protection value; This indicates the operation of finding the maximum value.

[0107] The servo driver generates the position envelope feature value, backlash envelope boundary value, and rigidity envelope boundary value according to the following formula:

[0108] ;

[0109] ;

[0110] ;

[0111] In the formula, Indicates the first Position envelope characteristic values ​​within a control clock cycle; Indicates the first Position deviation within one control clock cycle; Indicates the first The absolute value of the position deviation within each control clock cycle; Indicates the first The speed envelope coefficient within each control clock cycle; Indicates the first The gap envelope boundary value within each control clock cycle; Indicates the addressing index value The corresponding critical threshold for tooth gap determination; Indicates the first Rigid envelope boundary values ​​within each control clock cycle; Indicates the addressing index value The corresponding rigid transmission judgment margin; Indicates the first The address index value within each control clock cycle.

[0112] Because of 0 Therefore, the following condition is met:

[0113] ;

[0114] S306, the servo driver establishes the boundary logic for determining the drive state. The servo driver will use the position envelope feature values... Boundary value of the tooth gap envelope and rigid envelope boundary values Perform numerical comparison.

[0115] When the following equation is satisfied, the servo driver determines the transmission state to be backlash-through state:

[0116] ;

[0117] When the following formula is satisfied, the servo driver determines that the transmission state is in an elastic loading state:

[0118] ;

[0119] When the following formula is satisfied, the servo driver determines the transmission state to be rigid transmission:

[0120] ;

[0121] S307, backlash-through state indicates the operating stage where the internal gears of the planetary reducer are disengaged or within the idle clearance range; elastic loading state indicates the stress transition stage where the internal gears of the planetary reducer have made contact and caused structural torsional deformation; rigid transmission state indicates the operating stage where the torsional deformation of the internal structure of the planetary reducer reaches the preset rigid transmission judgment margin and is in a stable force transmission stage. The servo driver stores the transmission state judgment result in the random access memory area.

[0122] S308, the servo driver reads the historical drive state of the previous control clock cycle stored in the historical state register during the current control clock cycle, and performs a logical comparison between the historical drive state and the current drive state determined during the current control clock cycle.

[0123] Historical transmission status is represented as The current transmission state is represented as Among them, the gap-crossing state is represented as: The elastic loading state is represented as The rigid transmission dynamic representation is .

[0124] S309, the servo driver monitors the edge of the backlash change in the transmission state based on historical and current transmission states. When the historical transmission state in the previous control clock cycle was a non-backlash-through state (including elastic loading or rigid transmission states), and the current transmission state in the current control clock cycle is a backlash-through state, the servo driver triggers the transition flag. The transition flag is determined according to the following formula:

[0125] ;

[0126] In the formula, Indicates the first Transition flags within each control clock cycle; This indicates the historical transmission state of the previous control clock cycle; This indicates the current transmission state determined within the current control clock cycle; This indicates the gap crossing state.

[0127] The transition flag indicates the time point at which the internal mechanical structure of the planetary gearbox transitions from the torsional stage to the free play stage.

[0128] After the servo driver completes the transition judgment, it will change the current transmission state at the end of the current control clock cycle. Write the historical status register so that it serves as the historical transmission status in the next control clock cycle. use.

[0129] S310, the servo driver extracts the original quadrature-axis reference current signal from the current control loop based on the transition flag. The original quadrature-axis reference current signal is the quadrature-axis reference current signal generated by the proportional-integral control of the speed loop before the backlash-through state control branch intervenes.

[0130] When the jump flag is for At this time, the servo driver latches the original quadrature-axis reference current signal within the current control clock cycle as a boundary release current and records the control clock cycle index corresponding to the trigger time of the transition flag. The boundary energy release current is determined according to the following formula:

[0131] ;

[0132] In the formula, Indicates the boundary energy release current; Indicates the first The original quadrature axis reference current signal generated by the speed loop proportional-integral control within one control clock cycle; Indicates the first Transition flags within each control clock cycle; This represents the boundary release current held in the random access memory area at the previous time step.

[0133] S311, the servo driver will release the boundary current. Stored in the random access memory. During a single backlash-through state, the servo driver maintains the boundary release current unchanged; when the transmission state exits the backlash-through state and re-enters the elastic loading state or rigid transmission state, the servo driver releases the boundary release current lock and allows the boundary release current to be updated again when the next transition flag is triggered.

[0134] When the system first enters the backlash-through state after power-on and the boundary energy release current has not yet been initialized, the servo driver uses the current original quadrature-axis reference current signal, after limiting, as the initial value of the boundary energy release current:

[0135] ;

[0136] In the formula, Indicates the boundary energy release current; Indicates amplitude limiting operation; Indicates the first The original quadrature axis reference current signal generated by the speed loop proportional-integral control within one control clock cycle; Indicates the minimum allowable quadrature-axis reference current for output; This indicates the maximum permissible quadrature-axis reference current for output.

[0137] The S40 step includes the following sub-steps:

[0138] S401, the servo driver reads the transmission status from the random access memory. When the servo driver confirms that the transmission status is rigid, it triggers a pass-through branch in the instruction redirection logic. Rigid transmission indicates that the mechanical backlash inside the planetary gear reducer has been completely eliminated and the gears are in a stable force transmission range. Under the pass-through branch, the servo driver maintains the original closed-loop control data flow.

[0139] In S402, the servo driver performs speed loop proportional-integral (PI) control calculations and outputs the quadrature-axis reference current signal generated by the speed loop PI control calculations to the motor through the underlying current loop. The operation processes of the position loop calculations and the underlying space vector pulse-width modulation (PWM) output within the cascaded control framework can be accomplished by those skilled in the art by writing control algorithm code based on a conventional servo drive architecture. The basic closed-loop drive steps are well-known in the field and will not be elaborated upon here. The servo driver obtains the speed command from the control system. The servo driver calculates the speed deviation by subtracting the speed command from the smoothed angular velocity of the motor.

[0140] The S403 servo driver performs discretized proportional-integral mathematical calculations using speed deviation. The speed deviation is determined by the following formula:

[0141] ;

[0142] In the formula, Indicates the first Speed ​​deviation within each control clock cycle; Indicates the first Speed ​​command given within each control clock cycle; Indicates the first The smooth angular velocity of the motor within each control clock cycle.

[0143] Under rigid transmission dynamics, the servo driver updates the velocity loop integral term according to the following formula:

[0144] ;

[0145] In the formula, Indicates the first The integral term within each control clock cycle; This represents the integral term within the previous control clock cycle; Indicates the integral gain coefficient; Indicates the first Speed ​​deviation within each control clock cycle; This indicates the control clock cycle.

[0146] The original quadrature-axis reference current signal is generated according to the following formula:

[0147] ;

[0148] In the formula, Indicates the first The original quadrature axis reference current signal generated by the speed loop proportional-integral control within one control clock cycle; Indicates the proportional gain coefficient; Indicates the first Speed ​​deviation within each control clock cycle; Indicates the first The integral term within each control clock cycle.

[0149] In the S404, the servo driver does not add any additional compensation terms within the pass-through operation branch. The servo driver directly transmits the quadrature-axis reference current signal as the final current command to the motor. The motor generates electromagnetic torque based on the received quadrature-axis reference current signal to overcome load resistance and maintain stable operation of the mechanical system.

[0150] S405, the servo driver reads the transmission state from the random access memory. When the servo driver confirms the transmission state is in an elastic loading state, it triggers the feedforward superposition operation branch in the instruction redirection logic. The elastic loading state indicates that the gears inside the planetary reducer have reached physical contact and are in a stage of torsional deformation under stress. During this stage, part of the electromagnetic torque output by the motor is converted into the elastic potential energy of the mechanical structure, causing a lag in the actual driving torque transmitted to the load side.

[0151] S406, the servo driver reads the stiffness conversion coefficient from the non-volatile memory area, and simultaneously extracts the position deviation and the original quadrature-axis reference current signal generated by proportional-integral calculation from the random access memory area. The stiffness conversion coefficient integrates the torsional stiffness characteristics of the mechanical system and the electromagnetic torque constant of the motor, representing the proportional gain parameter that directly maps the mechanical deformation angle of the planetary reducer to the equivalent compensation current of the motor. The parameter tuning process for the servo driver to obtain the stiffness conversion coefficient can be completed by those skilled in the art using offline static load testing or frequency sweep identification. The mechanical stiffness parameter extraction step is a well-known technique in the field and will not be described in detail here.

[0152] In S407, the servo driver couples the position deviation with the original quadrature-axis reference current signal in the feedforward superposition operation branch. The servo driver calculates the deformation compensation current using the position deviation and stiffness conversion factor, and then superimposes this deformation compensation current onto the original quadrature-axis reference current signal. The final quadrature-axis reference current signal under elastic loading is determined by the following formula:

[0153] ;

[0154] In the formula, Indicates the first The final quadrature axis reference current signal within each control clock cycle; Indicates amplitude limiting operation; Indicates the first The original quadrature axis reference current signal generated by the speed loop proportional-integral control within one control clock cycle; Indicates the stiffness conversion factor; Indicates the first Position deviation within one control clock cycle; Indicates the minimum allowable quadrature-axis reference current for output; This indicates the maximum permissible quadrature-axis reference current for output.

[0155] The S408 servo driver outputs a final quadrature-axis reference current signal, including deformation compensation current, to the motor. The servo driver actively injects additional electromagnetic torque into the motor through feedforward calculations. This additional electromagnetic torque counteracts the energy absorbed during the mechanical elastic deformation process. The servo driver utilizes an active compensation mechanism to shorten the time span for torque buildup within the drivetrain.

[0156] S409, the servo driver reads the drive status from the random access memory. When the servo driver confirms that the drive status is in a backlash-through state, it triggers the anti-saturation damping substitution branch in the instruction redirection logic. The backlash-through state indicates that the planetary gearbox is in an idling range where the load is completely decoupled. Within this range, rotational motion on the motor side cannot be immediately transmitted to the load side.

[0157] S410, the servo drive suspends the update of the speed loop integral term under the anti-saturation damping substitution branch, and maintains the integral term value from the previous control clock cycle unchanged. The integral term is maintained according to the following formula:

[0158] ;

[0159] In the formula, Indicates the first The integral term within each control clock cycle; This represents the integral term within the previous control clock cycle. The servo driver prevents speed deviations from accumulating during backlash crossing and causing integral saturation by freezing the integral term.

[0160] S411, the servo driver extracts boundary release current from the random access memory area. And read the damping attenuation coefficient from the non-volatile storage area. The servo driver indexes the control clock cycle corresponding to the trigger time of the transition flag. Calculate the duration of the gap crossing state:

[0161] ;

[0162] In the formula, This indicates the time elapsed since the jump flag was triggered. Indicates the index of the current control clock cycle; Indicates the control clock cycle index corresponding to the trigger time of the transition flag; This indicates the control clock cycle.

[0163] The servo driver generates the final quadrature-axis reference current signal under backlash-crossing conditions according to the following formula:

[0164] ;

[0165] In the formula, Indicates the first The final quadrature axis reference current signal within each control clock cycle; Indicates amplitude limiting operation; Indicates the boundary energy release current; Represents the natural constant; Indicates the damping attenuation coefficient; This indicates the time elapsed since the jump flag was triggered. Indicates the minimum allowable quadrature-axis reference current for output; This indicates the maximum permissible quadrature-axis reference current for output.

[0166] S412, the servo driver outputs the final quadrature-axis reference current signal generated during the backlash-through state to the motor, and replaces the original speed loop output with this final quadrature-axis reference current signal during the backlash-through state. The servo driver guides the smooth release of the motor output torque through the discretely exponentially decaying quadrature-axis reference current signal, thereby reducing the angular acceleration of the motor when crossing the backlash range and reducing the mechanical impact force generated at the moment of re-engagement of the gear end faces.

[0167] When the transmission state switches from backlash crossing state to elastic loading state or rigid transmission state, the servo driver exits the anti-saturation damping substitution branch, resumes the speed loop proportional-integral control operation, and allows the boundary energy release current to be re-latched and updated when the next transition flag is triggered.

[0168] S413, the servo driver executes the control flow in the following order within each control clock cycle: synchronous sampling, position deviation calculation, state observer update, threshold mapping array addressing, transmission state determination, transition flag determination, current command redirection, and historical state update.

[0169] The historical state update is executed after the current command redirection to ensure that the next control clock cycle can use the transmission state of the previous control clock cycle as the historical transmission state. Through this execution sequence, the servo driver can continuously identify the switching relationship between backlash crossing state, elastic loading state, and rigid transmission state, and can generate corresponding quadrature axis reference current signals under different transmission states.

[0170] With the above settings, the servo driver can obtain the position deviation based on the motor-side position signal and the load-side position signal, and use the threshold mapping array to call the corresponding backlash determination critical threshold and rigid transmission determination margin according to different angular positions, thereby identifying the state changes of the planetary reducer between backlash crossing state, elastic loading state and rigid transmission state.

[0171] Under rigid transmission dynamics, the servo driver maintains speed loop proportional-integral control and underlying current loop control; under elastic loading, the servo driver superimposes deformation compensation current based on position deviation; under backlash crossing, the servo driver freezes the speed loop integral term and uses boundary energy release current to generate a discrete decay form of quadrature axis reference current signal.

[0172] Therefore, this embodiment can differentiate and control backlash, elastic deformation, and rigid transmission state without changing the mechanical structure of the planetary reducer, and can reduce the impact at the moment of gear re-meshing, thereby improving the control stability and position tracking accuracy of the planetary reducer servo transmission system.

[0173] Specific application examples:

[0174] The implementation background and parameter initialization are as follows:

[0175] In this embodiment, the controlled object is the base rotary joint of a certain type of semiconductor wafer handling robotic arm. Due to hardware cost constraints, the system uses a mature, commercially available single-stage planetary reducer (rated reduction ratio parameters). (10) Directly connected to a permanent magnet synchronous motor.

[0176] In step S10, given that the number of teeth on the internal gear ring of the planetary reducer is 45, and the planetary gear eccentricity is the main source of error, the servo driver acquires the characteristic number of teeth of the planetary reducer. It is 45.

[0177] Servo driver according to formula The spatial period was calculated. .

[0178] Setting discrete resolution parameters It is 0.00349 rad (approximately 0.2 degrees), according to the formula. Calculate the total number of discrete nodes. The value is 40. The servo driver establishes a threshold mapping array of length 40 in the non-volatile memory area.

[0179] After low-load and high-load calibration, the backlash of the rotary joint was measured to be different at different angles, and its tooth backlash determination critical threshold was determined. It exhibits sinusoidal fluctuations between 0.0015 rad and 0.0025 rad, with a rigid transmission decision margin. It fluctuates between 0.0045 rad and 0.0055 rad.

[0180] State observation and dynamic discrimination:

[0181] Control clock cycle when the robotic arm performs a reversing action. The control frequency is 125μs (8kHz). The servo driver synchronously reads data through a distributed clock mechanism and according to the formula... Continuous calculation of position deviation .

[0182] When the robotic arm issues a reverse movement command, the motor rotor begins to reverse, but the load remains in place due to inertia. At this time, the motor's smooth angular velocity... Increase, while smoothing the angular velocity on the load side. The absolute value of the positional deviation is close to 0. Rapid decline.

[0183] The servo driver performs envelope comparison, when the condition is met. When the position envelope feature value is less than the tooth gap envelope boundary value, the transmission state is determined to enter the tooth gap crossing state.

[0184] According to the formula Since the previous cycle was a non-backlash crossing state and the current cycle is a backlash crossing state, the servo driver triggers the transition flag and latches the original quadrature-axis reference current signal at the trigger moment, for example... The value is 3.2A, which is used as the boundary energy release current. Store 3.2A in the random access memory area.

[0185] Command redirection and its effect verification are as follows:

[0186] In the backlash-through state, the servo driver executes an anti-saturation damping substitution branch, according to the formula... Freeze the velocity loop integral term and apply the formula. Generate current. Set the damping attenuation coefficient. The value is 150. Within this range, the quadrature axis reference current decays exponentially and smoothly, preventing the motor from accelerating too quickly.

[0187] When the gear end faces re-engage Increase, satisfy When the system enters the elastic loading state, the feedforward superposition operation branch is triggered, according to the formula... Inject deformation compensation current to quickly build up torque.

[0188] Finally when At that time, it enters rigid transmission dynamics and resumes normal pass-through operation branch.

[0189] The experimental verification and effect comparison are explained as follows:

[0190] Reference Appendix Figure 3 , attached Figure 3 The horizontal axis represents the discrete index value (0 to 39), and the vertical axis represents the angle threshold parameter (rad). From Figure 3 As can be seen, due to the machining eccentricity inside the planetary reducer, the extracted backlash determination critical threshold and rigid transmission determination margin are not fixed constants within a spatial period, but exhibit a nonlinear spatial fluctuation distribution. This invention accurately maps this defect through the addressing mechanism.

[0191] Reference Appendix Figure 4 , attached Figure 4 The horizontal axis represents time (s), and the vertical axis represents the values ​​of the status bit and the flag bit. Figure 4 The solid line illustrates the evolution of the planetary gear reducer during reverse commutation, sequentially progressing through rigid transmission, elastic loading, backlash crossing, elastic loading, and back to rigid transmission. The dashed line accurately records the transition flag triggered at the fallback edge. pulse.

[0192] Reference Appendix Figure 5 , attached Figure 5 The horizontal axis represents time (s), and the vertical axis represents position deviation (rad). Under traditional closed-loop control (dashed line), due to the lack of backlash decoupling, the accumulation of the integral term leads to severe overshoot and prolonged oscillation (Limit Cycle) after crossing the backlash. The compensation control method of this invention (solid line) achieves this through state switching, allowing the position deviation to quickly and smoothly transition to the force zone after crossing the idle range, without significant overshoot.

[0193] Reference Appendix Figure 6 , attached Figure 6 The horizontal axis represents time (s), and the vertical axis represents the quadrature-axis reference current (A). After the transition flag is triggered, the conventional control (dashed line) causes the current command to spike rapidly due to the increased speed deviation; while the command redirection logic of this invention (solid line) successfully captures the boundary release current and generates a final quadrature-axis reference current signal with exponential decay characteristics during this period, actively suppressing the motor's no-load acceleration.

[0194] Reference Appendix Figure 7 , attached Figure 7 The horizontal axis represents time (s), and the vertical axis represents smoothed angular velocity (rad / s). Based on the internally constructed discrete state observer, the solid line (motor smoothed angular velocity) and the dashed line (load-side smoothed angular velocity) in the figure separate during the backlash crossing state (the load lags behind due to disengagement). After entering the rigid transmission state, high-precision speed coupling tracking is re-achieved, verifying the reliability of the observer in extracting speed data without phase shift.

[0195] Reference Appendix Figure 8 , attached Figure 8 The horizontal axis represents time (s), and the vertical axis represents the impact torque (Nm). Based on the aforementioned state monitoring and current damping attenuation strategy, the relative kinetic energy at the moment of gear re-contact is weakened. As can be seen from the comparison, compared with the traditional control (dashed line), the peak torque of gear impact is reduced by about 75% by the present invention (solid line), alleviating the pain point of accelerated accuracy decay in high-precision planetary reducers caused by long-term impact.

Claims

1. A compensation control system based on a high-precision planetary reducer, characterized in that, include: An electric motor is used to change the output torque. Planetary gear reducer, used to connect the motor; Motor-side encoder, used to generate motor-side position signals; Load-side encoder, used to generate load-side position signals; The servo driver is configured with a control clock cycle and internally operates a speed loop proportional-integral control and a low-level current loop control. It is used to calculate the position deviation based on the motor-side position signal and the load-side position signal, and the speed loop proportional-integral control generates the original quadrature axis reference current signal. A threshold mapping array is constructed in a non-volatile storage area, and the backlash determination critical threshold and rigid transmission determination margin are stored in the threshold mapping array. The transmission states are divided into backlash crossing state, elastic loading state, and rigid transmission state by combining the position deviation, the backlash determination threshold, and the rigid transmission determination margin. The backlash-through state refers to the operating stage where the internal gears of the planetary reducer are disengaged or within the range of free play; the elastic loading state refers to the stress transition stage where the internal gears of the planetary reducer have come into contact and have undergone structural torsional deformation; and the rigid transmission state refers to the operating stage where the internal structural torsional deformation of the planetary reducer has reached the preset rigid transmission judgment margin and is in a stable force transmission stage. According to the transmission state, the instruction redirection logic is executed and the original quadrature axis reference current signal is changed to obtain the final quadrature axis reference current signal, and the final quadrature axis reference current signal is transmitted to the motor.

2. The compensation control system based on a high-precision planetary reducer according to claim 1, characterized in that, The servo driver is used to extract the characteristic number of teeth of the planetary reducer, calculate the spatial period using the characteristic number of teeth, discretize the spatial period, read the discrete resolution parameter, calculate the total number of discrete nodes using the discrete resolution parameter and the spatial period, allocate a continuous storage address space in the non-volatile storage area according to the total number of discrete nodes, and establish the continuous storage address space as the threshold mapping array.

3. The compensation control system based on a high-precision planetary reducer according to claim 2, characterized in that, The servo driver is used to acquire the background response test data of the mechanical system, control the motor to perform forward operation, reverse operation and loading operation, synchronously record the feedback signals of the motor-side encoder and the load-side encoder, extract backlash width data and elastic deformation data, generate the backlash judgment critical threshold based on the backlash width data, and generate the rigid transmission judgment margin based on the elastic deformation data.

4. The compensation control system based on a high-precision planetary reducer according to claim 1, characterized in that, The servo driver is divided into a random access memory area. The servo driver is used to generate a synchronization trigger signal using an internal hardware timer, send the synchronization trigger signal to the motor-side encoder and the load-side encoder through a communication bus, read the absolute angle data latched in the motor-side encoder and the load-side encoder, convert the read angle values ​​into the motor-side position signal and the load-side position signal respectively, and store the motor-side position signal and the load-side position signal into the random access memory area.

5. A compensation control system based on a high-precision planetary reducer according to claim 1, characterized in that, The servo driver is used to read the rated reduction ratio parameter of the planetary reducer, use the rated reduction ratio parameter to calculate the motor-side position signal, and calculate the position deviation by subtracting the calculated motor-side position signal from the load-side position signal. The servo driver is also used to run a discrete state observer to process the motor-side position signal and the load-side position signal, extract speed information through the state convergence characteristics of the discrete state observer, directly derive the speed state quantity, and scale the speed state quantity into the smooth angular velocity of the motor and the smooth angular velocity of the load side.

6. A compensation control system based on a high-precision planetary reducer according to claim 5, characterized in that, The servo driver is used to perform a multiplicative envelope operation using the absolute value of the position deviation, the smoothed angular velocity of the motor, the smoothed angular velocity of the load side, the backlash determination threshold, and the rigid transmission determination margin to generate position envelope feature values, backlash envelope boundary values, and rigidity envelope boundary values. The position envelope feature values ​​are then compared with the backlash envelope boundary values ​​and the rigidity envelope boundary values. Based on the comparison results, the transmission state is divided into the backlash crossing state, the elastic loading state, and the rigid transmission state.

7. A compensation control system based on a high-precision planetary reducer according to claim 1, characterized in that, The servo driver is used to read the historical transmission state of the previous control clock cycle stored in the historical state register, and logically compare the historical transmission state with the current transmission state determined in the current control clock cycle. When the historical transmission state of the previous control clock cycle is a non-backlash crossing state and the current transmission state of the current control clock cycle is the backlash crossing state, a transition flag is triggered, the original quadrature axis reference current signal in the current control loop is extracted, and the original quadrature axis reference current signal is latched as a boundary energy release current according to the transition flag.

8. A compensation control system based on a high-precision planetary reducer according to claim 5, characterized in that, The servo driver is used to trigger the pass-through operation branch in the instruction redirection logic when the transmission state is confirmed to be the rigid transmission state. Under the pass-through operation branch, the original closed-loop control data stream is maintained, the speed command is obtained, the speed command is subtracted from the smooth angular velocity of the motor to obtain the speed deviation, the speed deviation is used to perform discrete proportional-integral mathematical calculation, the speed loop proportional-integral control operation is performed, and the original quadrature-axis reference current signal is directly transmitted to the motor as the final quadrature-axis reference current signal.

9. A compensation control system based on a high-precision planetary reducer according to claim 4, characterized in that, The servo driver is used to trigger the feedforward superposition operation branch in the instruction redirection logic when the transmission state is confirmed to be the elastic loading state. It reads the stiffness conversion coefficient, extracts the position deviation and the original quadrature axis reference current signal generated by the speed loop proportional-integral control from the random access memory, couples the position deviation and the original quadrature axis reference current signal under the feedforward superposition operation branch, calculates the deformation compensation current using the position deviation and the stiffness conversion coefficient, superimposes the deformation compensation current onto the original quadrature axis reference current signal, and transmits the final quadrature axis reference current signal containing the deformation compensation current to the motor.

10. A compensation control system based on a high-precision planetary reducer according to claim 7, characterized in that, The servo driver is used to trigger the anti-saturation damping substitution branch in the instruction redirection logic when the transmission state is confirmed to be the backlash crossing state. Under the anti-saturation damping substitution branch, the update of the speed loop integral term is paused, the integral term value of the previous control clock cycle remains unchanged, the damping attenuation coefficient is read, and the final cross-axis reference current signal under the backlash crossing state is generated using the boundary energy release current and the damping attenuation coefficient. The final cross-axis reference current signal is then transmitted to the motor.

Images