Servo motor drive and control equipment and control system

Abstract

This utility model relates to a drive and control device and a control system. The drive and control device includes: a low-voltage interface unit; a multi-axis control unit electrically connected to the low-voltage interface unit; a multi-axis drive unit electrically connected to the multi-axis control unit; and a high-voltage interface unit electrically connected to the multi-axis drive unit, and includes an AC power input port and a drive power output port for connecting a multi-axis robot.

Description

Technical Field

[0001] This application relates to the field of multi-axis robots, and in particular to a drive and control system for a servo motor used in a multi-axis robot. Background Technology

[0002] Multi-axis robots, also known as multi-degree-of-freedom robots or multi-axis robotic arms, are increasingly attracting attention due to their widespread application in various fields, leading to growing concerns about their control and actuation.

[0003] In related technologies, the controllers of each axis are often simply combined together as the controller of a multi-axis robot. Such controllers are highly complex and have difficulty in power factor correction. Utility Model Content

[0004] This application provides a drive and control device and a control system for servo motors in multi-axis robots to reduce the complexity of the drive and control device.

[0005] To address the aforementioned technical problems, the first aspect of this application provides a drive and control device for a servo motor of a multi-axis robot. The drive and control device includes: a low-voltage interface unit; a multi-axis control unit electrically connected to the low-voltage interface unit; a multi-axis drive unit electrically connected to the multi-axis control unit; and a high-voltage interface unit electrically connected to the multi-axis drive unit, and includes an AC power input port and a drive power output port for connecting the multi-axis robot.

[0006] To address the aforementioned technical problems, a second aspect of this application provides a control system for a multi-axis robot. This control system includes a motion controller for the multi-axis robot and a drive control device as described in the first aspect. The motion controller of the multi-axis robot is electrically connected to a low-voltage interface unit of the drive control device.

[0007] The servo motor drive and control system for multi-axis robots provided in this application can be equipped with separately integrated low-voltage interface units, multi-axis control units, multi-axis drive units, and high-voltage interface units, thereby improving the integration of the drive and control equipment. By setting a unified AC power input port and a drive power output port for connecting the multi-axis robot, this application can also uniformly correct the power factor of the multi-axis robot and uniformly control the current of the regenerative brake, thereby improving the efficiency of the multi-axis robot and reducing energy waste. Attached Figure Description

[0008] Figure 1 This is a schematic flowchart of a servo motor driving method for a multi-axis robot according to some embodiments of this application;

[0009] Figure 2This is a schematic flowchart of a servo motor driving method for a multi-axis robot according to some embodiments of this application;

[0010] Figure 3 According to some embodiments of this application, Figure 1 A flowchart illustrating step S50 in the process;

[0011] Figure 4 This is a schematic diagram of the structure of a servo motor drive device for a multi-axis robot according to some embodiments of this application;

[0012] Figure 5 This is a schematic diagram of the structure of a computer-readable storage medium for a multi-axis robot according to some embodiments of this application;

[0013] Figure 6 This is a drive and control device for a multi-axis robot according to some embodiments of this application;

[0014] Figure 7 This invention provides a schematic diagram of the structure of a multi-axis control unit according to some embodiments of the present application.

[0015] Figure 8 This invention provides a schematic diagram of the structure of a multi-axis drive unit according to some embodiments of the present application.

[0016] Figure 9 This is a structural schematic diagram of a high-voltage interface unit according to some embodiments of this application; and

[0017] Figure 10 This is a schematic diagram of the structure of a control system for a multi-axis robot according to some embodiments of this application. Detailed Implementation

[0018] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0019] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0020] In this article, the term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, "more" in this article means two or more objects.

[0021] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified in some embodiments. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0022] A multi-axis robot, also known as a multi-axis robotic arm, is an automated device capable of movement along multiple independent axial directions, widely used in industrial automation. The term "multi-axis" refers to the robot's ability to move along multiple degrees of freedom (usually called axes). These movements can be linear (e.g., forward / backward, up / down, left / right) or rotational (e.g., rotation, oscillation). The number of axes in a multi-axis robot typically determines its flexibility and adaptability. Common multi-axis robots include four-axis, six-axis, eight-axis, or robots with other numbers of axes.

[0023] Each axis of a multi-axis robot is typically equipped with at least one servo motor to perform motion that matches that axis or axial direction. Usually, one servo motor is configured per axis. In some cases, to meet the needs of high load or redundant design, multiple servo motors may be used to work together on the same axis.

[0024] Each servo motor on each axis is typically equipped with a feedback system. This feedback system may include encoders, linear encoders, or other position or speed measuring devices. For example, each servo motor may be configured with or include an encoder as part of the feedback system to monitor the motor's angle, speed, and position in real time. The encoder may be, for example, an incremental encoder or an absolute encoder; this application does not impose any specific limitations on this. The encoder can feed back the monitored information to the drive and / or control unit of the multi-axis robot.

[0025] A multi-axis robot may include at least one end effector. Servo motors of multiple axes of the multi-axis robot can work together to drive the end effector to perform specific movements.

[0026] Multi-axis robots can also be configured with motion controllers. Motion controllers can be, for example, real-time computing devices such as general-purpose computers, industrial computers, special-purpose computers, and industrial control computers. The motion controller can issue position request information to the multi-axis robot. This position request information may include, for example, trajectory planning for the end effector, the expected rotation angle, expected speed, and / or expected position for each servo motor. Some motion controllers also include input devices and / or display devices. Users of the multi-axis robot can interact with it through these input devices and / or display devices, such as inputting commands to the motion controller to control the robot's movement, or monitoring the robot's operating status through the display device.

[0027] In related technologies, each axis of a multi-axis robot is often controlled using only a feedback loop, and there is a lack of coordination between the controls of multiple axes. Given the high dynamic performance requirements of multi-axis robots, the control accuracy and response speed of this method are insufficient to meet the needs of industry.

[0028] In some embodiments, in addition to servo motors, multi-axis robots may also include other types of motors, such as torque motors, brushless DC motors, linear motors, stepper motors used in closed-loop systems, brushed DC motors, or induction motors, etc., and this application does not impose specific limitations. The following description uses servo motors as an example. Those skilled in the art should understand that the servo motors described below can be replaced with other types of motors.

[0029] To address the aforementioned technical problems, this application provides a novel method for driving servo motors in multi-axis robots.

[0030] refer to Figure 1 and Figure 2 , Figure 1 This is a schematic flowchart illustrating a method for driving servo motors in a multi-axis robot according to some embodiments of this application. Figure 2 This is a schematic flowchart illustrating a method for driving servo motors in a multi-axis robot according to some embodiments of this application.

[0031] In this application, the driving method can be executed by the multi-axis control unit (also called a multi-axis control board, multi-axis control chip, or multi-axis drive control board) of the drive and control device described below. Those skilled in the art should understand that this driving method can also be executed by other devices, and this application does not impose specific limitations. The following description uses an integrated drive and control device, particularly a multi-axis control unit, as an example to illustrate the driving method.

[0032] like Figure 1 As shown, the driving method of this application includes the following steps.

[0033] Step S10: Based on the expected position and current position of the servo motor, output speed feedback control information through the position feedback loop; based on the expected position of the servo motor, obtain speed feedforward control information.

[0034] In some embodiments, such as Figure 2 As shown, it can receive position request information from a multi-axis robot; and perform smoothing filtering on the position request information to obtain the expected position of the servo motor.

[0035] Users of multi-axis robots, or motion controllers for multi-axis robots as described above, can automatically plan the motion trajectory of the end effector of the multi-axis robot. The motion controller can then determine the position requirements of each of the multiple axes and the servo motors for each axis based on this motion trajectory. The position requirements can be, for example, a function of the servo motor's rotation angle and position over time; this application does not impose any specific limitations.

[0036] like Figure 2 As shown, the motion controller sends position request information to the multi-axis drive unit. In some embodiments, the multi-axis drive unit may first perform filtering processing on the position request information, such as smoothing filtering. Smoothing filtering can be, for example, moving average filtering, low-pass filtering, Gaussian filtering, adaptive filtering, etc. Smoothing filtering can eliminate noise in the position request information, reduce or weaken unnecessary high-frequency components in the position request information, making the movement of the multi-axis robot smoother, reducing vibration and impact on the mechanical parts of the multi-axis robot, and increasing its accuracy and service life.

[0037] In some embodiments, the operation of smoothing and filtering the position requirement information to obtain the expected position of the servo motor further includes: parsing and smoothing the position requirement information to obtain the expected position of the servo motor. The parsing process can be performed before or after the smoothing and filtering process, and this application does not impose specific limitations on this.

[0038] In some embodiments, the parsing process may include decoding, information format conversion, time interpolation, coordinate transformation, etc. Coordinate transformation, for example, involves converting position requirement information from a world coordinate system (Cartesian coordinates) to a joint space fixed to a specific axis or joint. In some embodiments, the communication between the motion controller and the drive unit is asynchronous; in this case, the parsing process may further include using timestamps or synchronization signals to ensure the temporal consistency of data across multiple axes. The position requirement information from the motion controller may include motion information from multiple axes. The drive unit may need to parse this position requirement information into the expected position for each servo motor.

[0039] In some embodiments, the expected position of the servo motor may be, for example, the position or angle of the servo motor at a certain point in time, or a series of positions or angles over a certain period of time.

[0040] In some embodiments, speed feedforward control information is obtained based on the expected position of the servo motor. This process can be similar to an open-loop control process. Specifically, the expected position of the servo motor is calculated by differentiation or differential calculation, and the result is used as speed feedforward control information for speed feedforward control.

[0041] For example, the expected position is a set of discrete expected position values ​​{P(t)}, where t is time. This can be achieved through... Figure 2 The differential in the system uses the finite difference method to perform differential calculation on the expected position value {P(t)}, and uses the differential calculation result, i.e. the corresponding velocity value, as the velocity feedforward control information.

[0042] In some embodiments, based on the expected position and the current position of the servo motor, speed feedback control information is output through a position feedback loop.

[0043] For details, please refer to Figure 2 The feedback system of the servo motor, such as a position sensor (e.g., an encoder, linear encoder, or other position measuring device), sends the current position of the servo motor to the multi-axis control unit. The multi-axis control unit calculates the difference between the expected position and the current position of the servo motor, i.e., the position deviation, also known as the position error. This position deviation is then input into the position feedback loop, and speed feedback control information is output.

[0044] The position feedback loop can be a closed-loop control loop. In some embodiments, the position feedback loop is a proportional-integral-derivative (PID) feedback control loop used for PID control. PID control is a linear control that uses a linear combination of the proportional (P) term, integral (I) term, and derivative (D) term of the deviation between the expected value (here, the expected position) and the actual value (here, the current position of the servo motor) to form a control quantity to control the controlled object. The proportional term represents the deviation, the integral term represents the accumulation of the deviation or the cumulative deviation, and the derivative term represents the rate of change of the deviation.

[0045] For example, if the error is e(t), then the output u(t) of the PID position feedback loop can be expressed as:

[0046]

[0047] In this formula, t represents time, and e(t) is the error that changes with time, also known as the proportional term of the error. That is, the accumulated error up to time t, also known as the integral term of the error; This refers to the rate of change of the error over time, also known as the differential term of the error. K P The weight of the proportional term, also known as the proportional gain parameter, K I The weight of the integral term, also known as the integral gain parameter, KD The weight of the differential term is also called the differential gain parameter.

[0048] Substituting the aforementioned position deviation into the PID output formula (1) yields the speed feedback control information. In the following text, substituting the speed deviation into the PID output formula (1) yields the current feedback control information, and substituting the current deviation into the PID output formula (1) yields the servo motor switching control signal.

[0049] In some embodiments, outputting velocity feedback control information through the position feedback loop includes: determining a first gain parameter of the position feedback loop; and outputting velocity feedback control information through the position feedback loop based on the first gain parameter. The first gain parameter includes the aforementioned proportional gain parameter, integral gain parameter, and derivative gain parameter.

[0050] In some embodiments, the first gain parameter can be determined by empirical value.

[0051] In some embodiments, the first gain parameter can be determined by a gain determination circuit. This gain determination circuit will be described in detail below.

[0052] Step S20: Superimpose speed feedback control information and speed feedforward control information to generate speed requirements.

[0053] refer to Figure 2 The speed feedback control information and speed feedforward control information output in step S10 above can be superimposed to obtain the speed requirement.

[0054] In some embodiments, the speed feedback control information and the speed feedforward control information can be weighted and summed to obtain the speed requirement. During the weighted summation process, the weights of the speed feedback control information and the speed feedforward control information can be set by the designer or user of the control unit according to specific circumstances; this application does not impose specific limitations.

[0055] Step S30: Based on the speed requirement and the current speed of the servo motor, output current feedback control information through the speed feedback loop; based on the speed requirement, obtain current feedforward control information.

[0056] In some embodiments, such as Figure 2 As shown, the speed requirement obtained in step S20 also needs to be checked to see if it exceeds the speed limit. If it does, the speed requirement can be reduced to obtain an updated speed requirement. This step prevents the servo motor from exceeding its maximum safe speed range, prevents drastic changes in speed requirement, or prevents excessive speed requirement from causing excessive load on the servo motor. In some scenarios involving human-computer interaction, speed limits can also protect personnel safety.

[0057] In some embodiments, current feedforward control information is obtained based on the expected speed in the servo motor's speed requirement. This process can be similar to an open-loop control process. Specifically, the expected speed of the servo motor is calculated using differentiation or differential calculation, and the result is used as current feedforward control information for current feedforward control.

[0058] For example, the expected velocity is a set of discrete expected velocity values ​​{V(t)}, where t is time. This can be achieved through... Figure 2 The differential in the circuit uses the finite difference method to perform differential calculations on the expected velocity value {V(t)}, and uses the differential calculation result, i.e. the corresponding current value, as the current feedforward control information.

[0059] In some embodiments, current feedback control information is output through a speed feedback loop based on the expected speed and the current speed of the servo motor.

[0060] For details, please refer to Figure 2 The feedback system of the servo motor, such as sensors like encoders, linear scales, or other measuring devices, can send the current speed feedback of the servo motor to the multi-axis control unit.

[0061] In some embodiments, such as Figure 2 As shown, the current speed output by the servo motor's feedback system can be calibrated before being sent to the multi-axis control unit. Speed ​​calibration can correct errors such as those in the encoder's feedback system and compensate for nonlinear characteristics occurring in the detection process. The calibrated speed feedback can more accurately reflect the dynamic changes of the servo motor, thereby helping to improve the system's response speed and reduce speed overshoot and undershoot. Speed ​​calibration enhances the stability and accuracy of the entire multi-axis control unit, thus providing a reliable foundation for high-performance motion control.

[0062] In some embodiments, the encoder may exhibit nonlinear errors (such as quantization errors or delays) at extremely low or high speeds. Speed ​​calibration can compensate for this nonlinearity using calibration curves to ensure measurement accuracy across the entire speed range.

[0063] The multi-axis control unit can calculate the difference between the expected speed and the current speed of the servo motor, i.e., the speed deviation of the servo motor, also known as the speed error. This speed deviation is then input into the speed feedback loop, and current feedback control information is output.

[0064] The speed feedback loop can be a closed-loop control loop. In some embodiments, similar to the position feedback loop described above, the speed feedback loop is also a PID feedback control loop used for PID control.

[0065] In the speed feedback loop, the error is the speed deviation. Substituting the speed deviation into the PID output formula (1) above, the current feedback control information can be obtained.

[0066] In some embodiments, outputting current feedback control information through the speed feedback loop includes: determining a second gain parameter of the speed feedback loop, wherein the second gain parameter includes the proportional gain parameter, integral gain parameter, and derivative gain parameter of the PID speed feedback loop; and outputting current feedback control information through the speed feedback loop based on the second gain parameter.

[0067] Step S40: Superimpose current feedback control information and current feedforward control information to generate current demand.

[0068] refer to Figure 2 The current feedback control information and current feedforward control information output in step S30 above can be superimposed to obtain the current demand. In some embodiments, the current feedback control information and current feedforward control information can be weighted and summed to obtain the current demand. During the weighted summation process, the weights of the current feedback control information and the current feedforward control information can be set by the designer of the control unit or the user according to specific circumstances, and this application does not impose specific restrictions.

[0069] In some embodiments, generating current demand by superimposing current feedback control information and current feedforward control information further includes: obtaining friction torque compensation based on the expected position of the servo motor; and superimposing current feedback control information, current feedforward control information, and friction torque compensation to generate current demand.

[0070] Specifically, such as Figure 2 As shown, the multi-axis control unit may include a friction torque compensation circuit. This circuit can output a friction torque compensation value based on a friction model, position requirements, and the parameters of the servo motor to be controlled. The friction torque compensation value can be weighted and summed with current feedback control information and current feedforward control information to offset the impact of friction on the servo motor performance, thereby improving the system's control accuracy and dynamic response capability.

[0071] In some embodiments, reference is made to Figure 2 Based on the input position requirement (e.g., position requirement after smoothing and filtering), the friction torque compensation circuit can determine the motion stage of the servo motor, such as the initial motion stage at the start, the low-speed motion stage, or the high-speed motion stage. Different types and states of servo motors result in different friction coefficients depending on the motion stage. The friction torque compensation circuit can adjust the friction torque compensation value according to the type and state of the servo motor and the specific motion stage to improve the control accuracy and dynamic performance of the servo motor.

[0072] Step S50: Based on the current demand and the actual current of the servo motor, generate a switching control signal for the servo motor through a current feedback loop.

[0073] In some embodiments, the current feedback loop is a proportional-integral-derivative feedback control loop.

[0074] In some embodiments, reference is made to Figure 3 , Figure 3 Some embodiments according to this application are shown. Figure 1 A flowchart illustrating step S50 in the diagram. (See attached flowchart.) Figure 3 As shown, step S50 includes the following steps.

[0075] S51: Apply filtering and / or current limiting to the current demand to obtain a second current demand.

[0076] In some embodiments, reference is made to Figure 2 This filtering process can be performed using a notch filter and / or a low-pass filter. A notch filter is a special type of band-stop filter used to significantly suppress or completely eliminate signals within a specific frequency range (typically a narrow band). A low-pass filter is a filter that allows low-frequency signals to pass through while suppressing or attenuating high-frequency signals. Both notch and low-pass filters can be used to suppress noise and vibration, thereby filtering out unwanted high-frequency signals and ensuring the stable operation of the servo motor.

[0077] In some embodiments, a current limit may be further applied to the filtered current demand. If the current limit is exceeded, the current demand can be reduced to obtain an updated second current demand. This step prevents the servo motor from exceeding its maximum safe current range, prevents excessively drastic changes in current demand, or prevents excessive current demand from causing excessive load on the servo motor. In some scenarios involving human-machine interaction, the current limit can also protect personnel safety. In some embodiments, the current limit can also prevent the servo motor torque from exceeding a safe torque value.

[0078] S52: Transform the actual current to obtain the direct-axis current value and / or quadrature-axis current value.

[0079] In some embodiments, the servo motor may include a current sensing sensor such as a Hall sensor, or the multi-axis drive unit described below may include a current detector. The current sensing sensor or current detector may output the current feedback value of the servo motor, also known as the actual current or actual current feedback value.

[0080] Servo motors typically consist of three phases of current, referred to as U-phase current, V-phase current, and W-phase current. In a balanced state, the sum of the three phase currents is zero. Current sensors or detectors can detect two of these phases; for example, they can detect only the U-phase current and the V-phase current as the actual current.

[0081] In some embodiments, the actual current can be transformed by CLARKE and PARK to obtain the direct-axis current value and / or quadrature-axis current value.

[0082] The Clarke transform is a mathematical transformation in electrical engineering that simplifies three-phase electrical analysis. It converts a balanced three-phase system into a mutually perpendicular two-phase system, facilitating signal processing. The Park transform projects the three-phase stator currents onto the direct axis (d-axis) and quadrature axis (q-axis) that rotate with the rotor, generating direct-axis and quadrature-axis currents. This diagonalizes the stator inductance matrix, simplifying the analysis of servo motor operation. This application will not elaborate further on the Clarke and Park transforms.

[0083] Specifically, direct-axis current is the current component along the direction of the motor's magnetic field (usually the direction of the rotor's magnetic field), mainly used to generate the magnetic field and control the motor's flux linkage. Quadrature-axis current is the current component perpendicular to the direction of the motor's magnetic field, mainly used to generate torque and is the primary power source for servo motors.

[0084] By using the Clarke transform and the Park transform, the actual current of the servo motor (i.e., the three-phase current; in the balanced three-phase system of the servo motor described in this application, only two-phase current, such as the U-phase current and the V-phase current, is required) can be converted into a two-axis current system that is easy to decouple and control, thereby improving control accuracy and efficiency.

[0085] S53: Obtain the current deviation between the second current requirement and the direct-axis current value and / or quadrature-axis current value.

[0086] In some embodiments, the second current requirement may include direct-axis current requirement and / or quadrature-axis current requirement, with at least quadrature-axis current requirement.

[0087] The step of obtaining the current deviation between the second current demand and the direct-axis current value and / or the quadrature-axis current value may include: subtracting the quadrature-axis current value from the quadrature-axis current demand, and using the difference as the quadrature-axis current deviation; and / or subtracting the direct-axis current value from the direct-axis current demand, and using the difference as the direct-axis current deviation.

[0088] S54: Based on the current deviation, current control information is generated through the current feedback loop.

[0089] In some embodiments, the quadrature-axis current deviation is input into the current feedback loop to generate quadrature-axis current control information, and / or the direct-axis current deviation is input into the current feedback loop to generate direct-axis current control information.

[0090] The current feedback loop can be, for example, the PID feedback control loop described above, which will not be elaborated further in this application. The obtained current control information may include quadrature-axis current control information and direct-axis current control information. The quadrature-axis current control information indicates the quadrature-axis current that needs to be applied to the servo motor, and the direct-axis current control information indicates the direct-axis current that needs to be applied to the servo motor.

[0091] S55: Generates the switching control signal for the servo motor based on the current control information.

[0092] In some embodiments, reference is made to Figure 2 The system can sequentially perform PARK inverse transform and space vector pulse width modulation on the quadrature-axis current control information and the direct-axis current control information. Specifically, it can perform PARK inverse transform and space vector pulse width modulation on the quadrature-axis current and direct-axis current to be applied to the servo motor to generate switching control signals for the servo motor. The switching control information is generally a pulse width modulation (PWM) signal.

[0093] The Parker Reverse Transformation (PRT) is the inverse of the Parker Transformation, converting direct-axis and quadrature-axis currents into three-phase currents, such as U-phase, V-phase, and W-phase currents. Space Vector Pulse Width Modulation (SVM) is an advanced pulse width modulation technique that optimizes the utilization and harmonic characteristics of the inverter output waveform through space vector analysis and dynamic modulation. This application will not elaborate further on either of these techniques.

[0094] In some embodiments, the switching control signal can be sent to a multi-axis drive unit. The inverter of the multi-axis drive unit can adjust the on / off state of its internal power switching devices (such as IGBTs or MOSFETs) according to the PWM signal, outputting the required three-phase AC power to the servo motor. Driven by this three-phase AC power, the servo motor performs various operations.

[0095] In some embodiments, such as Figure 2 As shown, the drive control device provided in this application also includes an overload monitor. The overload monitor can monitor the actual current, such as the direct-axis current and quadrature-axis current converted from the actual current. When the actual current exceeds the rated value, the overload monitor can issue an alarm or send a warning message to the multi-axis control unit. In some embodiments, when the warning message meets certain conditions, the multi-axis control unit can send a power cut-off command to the multi-axis drive unit. The multi-axis drive unit can, according to the power cut-off command, cut off the power supply to the servo motor matching the warning message, or switch the power supply of the entire multi-axis robot.

[0096] The driving method described in this application can improve the response speed, control accuracy, and robustness of the servo motor control process by combining feedforward control information and feedback control information.

[0097] The driving method of this application can coordinate and control multiple axes of a multi-axis robot or multiple servo motors of multiple axes. Specifically, the driving method of this application can control multiple servo motors in parallel or in a time-sharing manner.

[0098] In some embodiments, the driving method described above can determine a first gain parameter of the position feedback loop of the servo motor and / or a second gain parameter of the speed feedback loop, such that the weighted sum of at least two of the control errors of the position feedback loop, the control errors of the speed feedback loop, the total power factor error of the multi-axis robot, and the multi-axis synchronization error of the multi-axis robot is less than a threshold. This threshold can be set as needed, and this application does not impose specific limitations on it. For example, the first gain parameter of the position feedback loop and the second gain parameter of the speed feedback loop can be determined by a gain determination circuit. The determination of the first gain parameter and the second gain parameter can be coordinated. For example, the first gain parameter of the position feedback loop that meets the above requirements can be determined first, and then the second gain parameter of the speed feedback loop can be determined based on the first gain parameter.

[0099] Specifically, control error refers to the deviation between the feedback value and the target value, and can be used to characterize the accuracy of the control system. For example, the control error of the position feedback loop is the deviation e of the position fed back by the servo motor from the position requirement. p The control error of the speed feedback loop is the deviation e of the speed fed back by the servo motor from the speed requirement. v .

[0100] Specifically, the total power factor error e tp Total power factor error (TFE) refers to the deviation between the actual power factor and the ideal power factor of a multi-axis robot, used to evaluate the energy utilization efficiency or energy efficiency optimization level of the multi-axis robot. In other words, TFE is the ratio of the total active power to the total apparent power of all servo motors in a multi-axis robot.

[0101] Specifically, the multi-axis synchronization error term e c This reflects the synchronization deviation between the axes of a multi-axis robot when performing coordinated movements. The synchronization error term is used to evaluate the coordination of a multi-axis system. For example, the multi-axis synchronization error term can be characterized by calculating the deviation between the expected motion trajectory or position of the end effector and the actual motion trajectory or position.

[0102] By considering the total power factor error of the multi-axis robot when determining the first gain parameter of the position feedback loop and the second gain parameter of the velocity feedback loop, the total power consumption of the multi-axis robot can be reduced. By considering the multi-axis synchronization error term of the multi-axis robot when determining the first gain parameter of the position feedback loop and the second gain parameter of the velocity feedback loop, this application can achieve coordinated control of multiple axes of the multi-axis robot.

[0103] In some embodiments, determining the first gain parameter of the position feedback loop includes: determining the first gain parameter of the position feedback loop through a gain determination circuit based on a first scheduling variable. The first scheduling variable includes a first global scheduling variable for the multi-axis robot and a first local scheduling variable for the servo motors.

[0104] In some embodiments, the first global scheduling variable and / or the second global scheduling variable includes at least one of the following: the current application scenario of the multi-axis robot; the expected motion trajectory of the end effector matched with the servo motor; the load parameters of multiple axes of the multi-axis robot; or, the power factor correction parameters of the multi-axis robot.

[0105] In some embodiments, the first local scheduling variable includes at least one of the following: the current position deviation fed back by the servo motor, the position requirement, the speed feedforward information, or the current first gain parameter.

[0106] In some embodiments, the gain determination circuit may determine a first gain parameter based on a first global scheduling variable and a first local scheduling variable to ensure that the weighted sum of at least two of the control error of the position feedback loop, the total power factor error of the multi-axis robot, and the multi-axis synchronization error of the multi-axis robot is less than a threshold.

[0107] In some embodiments, determining the second gain parameter of the speed feedback loop includes: determining the second gain parameter of the speed feedback loop through a gain determination circuit based on a second scheduling variable. The second scheduling variable includes a second global scheduling variable for the multi-axis robot and a second local scheduling variable for the servo motors.

[0108] In some embodiments, the first global scheduling variable and the second global scheduling variable may be the same, and are collectively referred to as global gain scheduling variables.

[0109] In some embodiments, the second local scheduling variable includes at least one of the following: current speed deviation, expected speed, current feedforward information, updated first gain parameter, current second gain parameter, or expected switching time of the first gain parameter.

[0110] In some embodiments, when the inertia of the servo motor or the end effector is large, or to prevent sudden changes in the parameters of the servo motor, the switching of the first gain parameter and / or the second gain parameter may be delayed. Instead, the switching of the first gain parameter and / or the second gain parameter is set to occur at a delayed, expected switching time. In some embodiments, if the difference between the expected switching time of the first gain parameter and the current time, i.e., the delayed switching time, exceeds a threshold, the second gain parameter may not require delayed switching.

[0111] In some embodiments, the gain determination circuit may determine a second gain parameter based on the first gain parameter, the second global scheduling variable, and the second local scheduling variable determined above, to ensure that the weighted sum of at least two of the control error of the speed feedback loop, the total power factor error of the multi-axis robot, and the multi-axis synchronization error of the multi-axis robot is less than a threshold.

[0112] In the driving method of this application, for example, the first gain parameter of the position feedback loop and the second gain parameter of the speed feedback loop of each servo motor can be automatically updated or switched by the gain determination circuit, so as to comprehensively consider the control efficiency of the servo motors of multiple axes of the multi-axis robot, the total power factor correction and the synchronous coordination of multiple axes, thereby improving the control efficiency of the multi-axis robot and reducing its operating cost.

[0113] In some embodiments, the gain determination circuit may be, for example, a circuit that includes a machine learning model.

[0114] refer to Figure 4 , Figure 4 This is a schematic diagram of a servo motor drive device 100 for a multi-axis robot according to some embodiments of this application. The drive device 100 may include at least the multi-axis drive unit or multi-axis drive circuit described above. Figure 4 As shown, the drive device 100 includes a processor 120 and a memory 110. The memory 110 stores a computer program. The processor 120 is configured to execute the computer program to implement the drive methods described in the embodiments above.

[0115] refer to Figure 5 , Figure 5 This is a schematic diagram of a computer-readable storage medium 200 for a multi-axis robot according to some embodiments of this application. The computer-readable storage medium 200 stores a computer program 210. When executed by a processor, the computer program 210 implements the driving methods described in the various embodiments above.

[0116] refer to Figure 6 , Figure 6 According to some embodiments of this application, a drive and control device 400 for a multi-axis robot 300 is provided. This drive and control device is an integrated drive and control unit. For example... Figure 6As shown, the drive control device 400 may include a low-voltage interface unit 410, a multi-axis control unit 420, a multi-axis drive unit 430, and a high-voltage interface unit 440.

[0117] Specifically, the low-voltage interface unit 410 can be configured to connect to the multi-axis robot 300 and / or the motion controller 500 for the multi-axis robot 300 to receive servo status and position request information from the multi-axis robot 300. Servo status may be, for example, the load status of a servo motor, current feedback value, speed feedback value, or position feedback value. For example, the low-voltage interface unit 410 can be configured to receive servo status from the multi-axis robot 300. The low-voltage interface unit 410 can also be configured to receive position request information from the motion controller 500.

[0118] The low-voltage interface unit 410 can also be called a low-voltage interface board (Misc Interface Board), low-voltage interface unit, low-voltage interface board, low-voltage interface circuit, or communication interface, etc.

[0119] The low-voltage interface unit 410 includes a standard protocol interface 411, also known as a standard protocol communication interface, such as an Ethercat network interface or an Ethercat input / output port, which enables communication with multi-axis robots 300 of different types and with different numbers of axes. The low-voltage interface unit 410 may also include at least one of a safety link interface 412, a brake control interface 413, and a user debugging external interface 414.

[0120] The low-voltage interface unit 410 includes an isolation circuit 415 that is electrically or communicatively interconnected with the standard protocol interface 411. The isolation circuit 415 may be, for example, an optocoupler or other isolation circuit, an isolator, or a signal isolator. The multi-axis control unit 420 is connected to the standard protocol interface 411 via the isolation circuit 415.

[0121] In the embodiments of this application, the low-voltage interface unit 410 can integrate the low-voltage communication function of the drive and control device 400, simplifying the complexity of the drive and control device 400. Furthermore, the low-voltage interface unit 410 can be loosely coupled with the motion controller 500 of the multi-axis robot 300 through the standard protocol interface 411, enhancing the applicability of the drive and control device 400.

[0122] Specifically, the multi-axis control unit 420 is configured to be electrically connected to the low-voltage interface unit 410 to receive the aforementioned servo status and position request information. The multi-axis control unit 420 is also referred to as a multi-axis drive control board (DCBM), multi-axis control circuit, etc.

[0123] In some embodiments, the multi-axis control unit 420 may be configured to receive servo status and position demand information from the low-voltage interface unit 410, and to implement the driving method as described in the above embodiments to output switching control signals, such as PWM signals, for the servo motors of the multiple axes of the multi-axis robot 300.

[0124] In some embodiments, the multi-axis control unit 420 communicates with the motion controller 500 of the multi-axis robot 300 via a low-voltage interface unit 410 (such as an ETHERCAT slave station), thereby receiving motion commands from the motion controller 500 of the multi-axis robot 300.

[0125] refer to Figure 7 , Figure 7 A schematic diagram of the structure of a multi-axis control unit 420 according to some embodiments of this application is shown.

[0126] like Figure 7 As shown, the multi-axis control unit 420 is a system-on-a-chip (SOC) 421, or includes a system-on-a-chip (SOC) 421. The multi-axis control unit 420 also includes a storage circuit 422, a debugging circuit 423, a servo motor control and feedback circuit 424 connected to the system-on-a-chip 421, and a monitoring circuit 425 for electrical connection to the multi-axis drive unit 430. The monitoring circuit 425 is also called the multi-axis drive unit monitoring circuit.

[0127] The debugging circuit 423 can be connected to the low-voltage interface unit 410, specifically through the isolation circuit 415 to the user debugging external interface 414 of the low-voltage interface unit 410. The debugging circuit 423 may include, for example, a debug RS232 or a debug RS422 interface, etc., and this application does not impose any specific limitations on it.

[0128] The storage circuit 422 may be, for example, a synchronous dynamic random access memory (SDRAM), an electrically erasable programmable read-only memory (EEPROM), a four-wire serial peripheral interface flash memory (QSPI FLASH), a micro security digital card (Micro SD), etc., and this application does not impose any specific limitations on it.

[0129] The servo motor control and feedback circuit 424 can receive feedback from the encoder of the multi-axis robot 300, or current value information from the multi-axis robot 300, through the low-voltage interface unit 410. The servo motor control and feedback circuit 424 can be connected to the multi-axis drive unit 430.

[0130] The monitoring circuit 425 of the multi-axis control unit 420 can be connected to the multi-axis drive unit 430 to monitor the status of the multi-axis drive unit 430.

[0131] In some embodiments, the multi-axis control unit 420 may include multiple sub-axis control circuits, each of which is used to output the speed, position, and current requirements of the servo motor for each axis. For example, the multi-axis control unit 420 may include four, six, eight, or more sub-axis control circuits. Optionally, multiple axes may share the same sub-axis control circuit; this application does not impose specific limitations on this.

[0132] In some embodiments, the multi-axis control unit 420 may include a gain determination circuit, also known as a gain switching circuit. This gain determination circuit can be used to generate corresponding first and second gain parameters for multiple sub-axis control circuits to ensure coordination among the multiple axes and perform power factor correction for the multiple axes.

[0133] The multi-axis drive unit 430 can be electrically connected to the multi-axis control unit 420. The multi-axis drive unit 430 is also called a multi-axis drive power board (DPBM) or multi-axis drive circuit.

[0134] refer to Figure 8 , Figure 8 A schematic diagram of the structure of a multi-axis drive unit 430 according to some embodiments of this application is shown. Figure 8 As shown, the multi-axis drive unit 430 includes an AC power supply switch 431 for AC power supply, a rectifier 432, a power factor correction circuit 433, a DC bus 434, and an IPM inverter 435, which are connected in sequence for AC power supply.

[0135] The IPM inverter 435 can be electrically connected to the drive power output port of the high-voltage interface unit 440 to receive the switching control signal of the servo motor. The IPM inverter 435 may include IGBT switches, etc., to perform on / off switching according to the switching control signal for driving the servo motor.

[0136] AC power switch 431 is a switch for AC power supply. AC power switch 431 is electrically connected to multi-axis control unit 420. Multi-axis control unit 420 is configured to control the on / off state of AC power switch 431. Specifically, multi-axis control unit 420 can be configured to disconnect AC power switch 431 under certain conditions, such as in an emergency, to cut off the operation of multi-axis robot 300. AC power switch 431 is electrically connected to the AC power input port of high-voltage interface unit 440 to receive high-voltage AC power from an external source.

[0137] The power factor correction circuit 433 is used to correct the power factor to improve the overall power factor of the multi-axis robot 300. In some embodiments, the power factor correction circuit 433 also has a boost function.

[0138] In some embodiments, the multi-axis drive unit 430 is configured to receive AC power from an AC power supply via a high-voltage interface unit 440 and generate three-phase currents for the servo motors of the multiple axes based on switch control signals.

[0139] The high-voltage interface unit 440 can be electrically connected to the multi-axis drive unit 430, AC power supply, regenerative brake, and multi-axis robot 300. The high-voltage interface unit 440 is also called a high-voltage interface board (HV Interface Board), high-voltage interface voltage, high-voltage interface circuit, high-voltage interface board, etc.

[0140] For details, please refer to Figure 9 , Figure 9 This is a structural schematic diagram of a high-voltage interface unit 440 according to some embodiments of this application. For example... Figure 9 As shown, the high-voltage interface unit 440 may include an AC power input port 441 and a drive power output port 442 for connecting to the multi-axis robot 300. The AC power input port 441 is used for external AC power input. The drive power output port 442 is used for three-phase power output to drive the servo motor.

[0141] The high-voltage interface unit 440 may also include a regenerative brake interface 443 for connecting an external regenerative brake, such as a regenerative braking resistor. The regenerative brake is used to absorb and dissipate the regenerative energy fed back to the multi-axis drive unit 430 by the servo motor when the servo motor is in regenerative braking state, thereby protecting the safe operation of the multi-axis robot 300 and the drive and control equipment 400.

[0142] In the embodiments of this application, the DC bus 434 of the multi-axis drive unit 430 can be connected to the regenerative brake interface 443. Specifically, the DC bus 434 is connected to an external regenerative brake through the regenerative brake interface 443 of the high-voltage interface unit 440. Since the drive and control device 400 of this application can simultaneously drive and control servo motors of multiple axes, the multi-axis drive unit 430 of this application can distribute the regenerative energy fed back by multiple servo motors before the servo motors of different axes, thereby reducing the energy output to the regenerative brake, reducing the heat generation of the regenerative brake, and improving the energy consumption of the multi-axis robot 300. In addition, the multi-axis drive unit 430 of this application only needs to be connected to one regenerative brake, reducing the complexity of the system.

[0143] The servo motor control and feedback circuit 424 and the monitoring circuit 425 for the multi-axis drive unit 430 are respectively connected to the multi-axis drive unit 430.

[0144] refer to Figure 10 , Figure 10This application illustrates a control system 600 for a multi-axis robot 300 according to some embodiments. The control system 600 may, for example, be a control cabinet for the multi-axis robot 300. The control system 600 may include a motion controller 500 for the multi-axis robot 300 and, for example, a control cabinet for the multi-axis robot 300. Figure 6 The drive control device 400 is shown. The motion controller 500 of the multi-axis robot 300 is electrically connected to the low-voltage interface unit 410 of the drive control device 400.

[0145] In this application, the processor may also be referred to as a CPU (Central Processing Unit). The processor may be an integrated circuit chip with signal processing capabilities. The processor may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor may be a microprocessor or any conventional processor. Furthermore, the processor may be implemented using integrated circuit chips.

[0146] In some embodiments, the functions or modules of the apparatus provided in this disclosure can be used to perform the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0147] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0148] In the several embodiments provided in this application, it should be understood that the disclosed methods and apparatus can be implemented in other ways. For example, the apparatus implementations described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0149] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0150] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0151] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A drive device for a servo motor of a multi-axis robot, characterized by, include: Low-voltage interface unit; The multi-axis control unit is electrically connected to the low-voltage interface unit; A multi-axis drive unit is electrically connected to the multi-axis control unit; as well as The high-voltage interface unit is electrically connected to the multi-axis drive unit and includes an AC power input port and a drive power output port for connecting the multi-axis robot.

2. The drive and control device according to claim 1, characterized in that, The low-voltage interface unit includes a standard protocol communication interface and an isolation circuit that are interconnected. The multi-axis control unit is connected to the standard protocol communication interface via the isolation circuit.

3. The drive and control device according to claim 2, characterized in that, The low-voltage interface unit also includes at least one of a safety link interface, a brake control interface, and a user debugging external interface.

4. The drive and control device according to claim 2, characterized in that, The standard protocol communication interface includes Ethercat input / output ports.

5. The drive and control device according to claim 1, characterized in that, The multi-axis control unit includes a system-on-a-chip.

6. The drive and control device according to claim 5, characterized in that, The multi-axis control unit also includes a storage circuit, a debugging circuit, a servo motor control and feedback circuit, and a multi-axis drive unit monitoring circuit connected to the system single chip; The debugging circuit is connected to the low-voltage interface unit; as well as The servo motor control and feedback circuit and the multi-axis drive unit monitoring circuit are respectively connected to the multi-axis drive unit.

7. The drive and control device according to claim 1, characterized in that, The multi-axis drive unit includes an AC power supply switch, a rectifier, a power factor correction circuit, a DC bus, and an IPM inverter connected in sequence. The AC power supply switch is electrically connected to the AC power input port of the high-voltage interface unit; and The IPM inverter is electrically connected to the drive power output port of the high-voltage interface unit.

8. The drive and control device according to claim 7, characterized in that, The high-voltage interface unit includes a regenerative brake interface; and The DC bus is electrically connected to the regenerative brake interface.

9. The drive and control device according to claim 7, characterized in that, The AC power supply switch is electrically connected to the multi-axis control unit.

10. A control system for a multi-axis robot, characterized by Includes a motion controller for a multi-axis robot and a drive control device according to any one of claims 1-9. The motion controller of the multi-axis robot is electrically connected to the low-voltage interface unit of the drive and control device.

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