Servo control method, device and system and servo driver

Abstract

The invention discloses a servo control method, device and system and a servo driver, and relates to the technical field of servo, the method is realized by the servo driver, the method comprises the following steps: receiving a control instruction sent by an upper controller, receiving feedback signals of servo motors, each servo motor is provided with an encoder, and the encoder is connected with the upper controller; the plurality of encoders are connected in series through encoder lines, a feedback signal is sent by the encoder line at the serial tail end, a servo motor control signal is generated according to a control instruction and the feedback signal, and the servo motor control signal is sent to each servo motor through a plurality of motor power lines.

Description

Technical Field

[0001] The present application relates to the field of servo technology, and in particular, to a servo control method, device, system and servo driver. Background Art

[0002] A servo system is a system composed of a servo motor and a servo drive, where a servo motor is an engine that controls the operation of mechanical components in a servo system. It is an auxiliary motor indirect speed change device. The rotor speed of a servo motor is controlled by an input signal and can respond quickly. In an automatic control system, it is used as an actuator and has the characteristics of a small electromechanical time constant, high linearity, and starting voltage. An encoder is installed on the servo motor to convert the received electrical signal into an angular displacement or angular velocity output on the motor shaft. A servo drive is a device used to drive a servo motor to move. The servo drive directly receives the control instructions of the controller. Existing servo drives generally support control methods such as direction + pulse and industrial bus. One servo drive controls one servo motor. An industrial robot is generally composed of four or six joints, each of which has a servo motor. The servo motor has an encoder line and a power line. The servo drive and the servo motor drive the motor to rotate through the power line, and the position and speed information are fed back through the encoder line. Generally, servo drives are placed in electrical control cabinets, which are separated from the industrial robot body and far away from each other. There are many connecting wires between the servo drive and the servo motor, which makes installation difficult, and the corresponding joints are easily connected incorrectly. The cable cost is high, and the encoder signal line is thin, which is prone to breakage, poor contact, short circuit and other problems. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, the present application provides a servo control method, device, system and servo driver.

[0004] The technical solution adopted by this application to solve its technical problem is:

[0005] In a first aspect, a servo control method is provided, the method being implemented by a servo driver, the method comprising:

[0006] Receive control instructions sent by the upper controller;

[0007] Receiving feedback signals from servo motors, each servo motor is provided with an encoder, and multiple encoders are serially connected through encoder lines, and the feedback signals are sent by the encoder lines at the end of the serial connection;

[0008] Generate a servo motor control signal according to the control instruction and the feedback signal;

[0009] The servo motor control signal is sent to each servo motor through a plurality of motor power lines.

[0010] Furthermore, before generating the servo motor control signal according to the control instruction and the feedback signal, the method also includes: decoding the feedback signal to obtain a position feedback signal; forwarding the position feedback signal directly to the host controller so that the host controller generates a position control signal according to the control instruction and the position feedback signal; receiving the position control signal sent by the host controller; sending the servo motor control signal to each servo motor through multiple motor power lines: sending the servo motor control signal and the position control signal to each servo motor through multiple motor power lines.

[0011] Furthermore, the feedback signal also includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and generating the servo motor control signal according to the control instruction and the feedback signal includes: generating the speed control signal according to the control instruction and the speed feedback signal; generating the matrix control signal according to the output current of the servo driver.

[0012] In a second aspect, a servo drive device is provided, comprising:

[0013] A bus transceiver unit is used to receive control instructions sent by the upper controller and receive feedback signals from the servo motors. Each servo motor is provided with an encoder. Multiple encoders are serially connected through encoder lines. The feedback signal is sent by the encoder line at the end of the serial connection. The servo motor control signal is sent to each servo motor through multiple motor power lines.

[0014] The DSP processor is used to generate a servo motor control signal according to the control instruction and the feedback signal.

[0015] Furthermore, it also includes: a bus encoder decoding unit, which is used to decode the feedback signal to obtain a position feedback signal; the bus transceiver unit is also used to forward the position feedback signal directly to the host controller, so that the host controller can generate a position control signal according to the control instruction and the position feedback signal, receive the position control signal sent by the host controller, and send the servo motor control signal and the position control signal to each servo motor through multiple motor power lines.

[0016] Furthermore, the feedback signal also includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and the servo driver also includes: the DSP processor is also used to generate the speed control signal according to the control instruction and the speed feedback signal, and generate the matrix control signal according to the output current of the servo driver.

[0017] Furthermore, it also includes: multiple inverter drive units for driving and controlling the inverter units; multiple inverter units for converting power into AC power, and generating AC voltage and current output to the servo motor according to the drive signal of the inverter drive unit.

[0018] In a third aspect, a servo drive system is provided, comprising:

[0019] The upper controller is used to obtain control instructions and send the control instructions to the servo driver;

[0020] A servo driver, configured to receive the control instruction, receive a feedback signal from an encoder, generate a servo motor control signal according to the control instruction and the feedback signal, and send the servo motor control signal to each servo motor through a plurality of motor power lines;

[0021] A plurality of servo motors, each servo motor is provided with an encoder, the plurality of encoders are connected in series through encoder lines, the encoder lines at the ends of the series are connected to the servo driver, and each encoder sends the feedback signal to each servo driver through the encoder line.

[0022] Furthermore, after receiving the feedback signal, the servo driver decodes the feedback signal to obtain a position feedback signal, forwards the position feedback signal directly to the host controller, receives the position control signal sent by the host controller, and sends the servo motor control signal and the position control signal to each servo motor through multiple motor power lines; the host controller includes a position loop circuit, which receives the position feedback signal sent by the servo driver, generates a position control signal according to the control instruction and the position feedback signal, and sends the position control signal to the servo driver.

[0023] Furthermore, the servo driver is also used to receive the position control signal. The servo driver includes a speed loop circuit and a current loop circuit. The speed loop circuit generates a speed control signal according to the control instruction and the speed feedback signal. The current loop circuit detects the output current of the servo driver. The current loop circuit generates a matrix control signal according to the output current.

[0024] In a fourth aspect, a servo driver is provided, comprising:

[0025] at least one processor and at least one memory;

[0026] The memory stores executable instructions of the processor;

[0027] The processor is configured to execute any one of the above servo control methods.

[0028] The technical solution of the present application provides a servo control method, device, system and servo driver. The method receives control instructions sent by a host controller and receives feedback signals from a servo motor. Each servo motor is provided with an encoder. Multiple encoders are connected in series through encoder lines. The feedback signal is sent by the encoder line at the end of the serial line. A servo motor control signal is generated according to the control instructions and the feedback signal. The servo motor control signal is sent to each servo motor through multiple motor power lines. Multiple encoders are connected in series, thereby reducing the number of wiring connections between the servo motor and the servo driver and effectively improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a flow chart of a servo control method provided by an embodiment of the present application;

[0031] Figure 2 is a flow chart of another servo control method provided by an embodiment of the present application;

[0032] Figure 3 is a functional structure diagram of a servo control device provided in an embodiment of the present application;

[0033] Figure 4 Schematic diagram of the functional structure of the inverter drive unit and the inverter unit in the embodiment of the present application;

[0034] Figure 5 It is a functional structure diagram of a servo control system provided by an embodiment of the present application;

[0035] Figure 6 is a schematic diagram of the internal functional structure of a servo control system provided by an embodiment of the present application;

[0036] Figure 7 It is a functional structure diagram of the servo driver provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application is described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0038] To solve the above problems, refer to Figure 1 , an embodiment of the present application provides a servo control method, which is implemented by a servo driver, and the method includes:

[0039] 101. Receive control instructions sent by the upper controller.

[0040] 102. Receive feedback signals from servo motors. Each servo motor is provided with an encoder. Multiple encoders are serially connected via encoder lines. Feedback signals are sent by the encoder lines at the end of the serial connection.

[0041] 103. Generate a servo motor control signal according to the control command and the feedback signal.

[0042] 104. Send a servo motor control signal to each servo motor via a plurality of motor power lines.

[0043] The servo control method provided in this embodiment receives control instructions sent by a host controller; receives feedback signals from servo motors, each servo motor is provided with an encoder, multiple encoders are serially connected through encoder lines, and feedback signals are sent by the encoder lines at the end of the serial line; generates servo motor control signals according to the control instructions and feedback signals; sends servo motor control signals to each servo motor through multiple motor power lines, and multiple encoders are serially connected, thereby reducing the number of wiring connections between the servo motor and the servo driver and effectively improving the user experience.

[0044] In the related art, the encoder circuits of multiple servo motors are complicated, which can easily cause circuit failures during use. The servo drive needs to transmit data to the upper controller at intervals of a certain transmission cycle, which makes the upper controller obtain the encoder data of each axis of the actual robot with a large time delay, resulting in the motion control instructions being not precise and accurate enough. In addition, in the traditional servo drive system, due to the delay and asynchrony of the position data, the control instructions given by the upper controller to the servo drive are delayed, which greatly increases the reaction time of the robot. In order to solve the above problems, as an improvement on the above embodiments, an embodiment of the present invention provides another servo control method, which can reduce the cost of cable connection, reduce the difficulty of installation, reduce the maintenance cost, set the position loop in the upper controller, and the upper controller can read the encoder signal faster, so as to realize more accurate real-time control of the robot and reduce the difficulty of debugging the servo drive. Only the speed loop and the current loop need to be debugged. The upper controller can directly read the encoder signal for monitoring and calculation, which reduces the delay and is separated from the drive calculation processing. Figure 2 , the method comprising:

[0045] 201. Receive control instructions sent by a host controller.

[0046] 202. Receive feedback signals from servo motors. Each servo motor is provided with an encoder. Multiple encoders are serially connected via encoder lines. Feedback signals are sent by the encoder lines at the serial ends. The feedback signals include position feedback signals and speed feedback signals.

[0047] 203. Decode the feedback signal to obtain a position feedback signal.

[0048] 204. Forward the position feedback signal directly to the upper controller, so that the upper controller generates a position control signal according to the control instruction and the position feedback signal.

[0049] 205. Receive the position control signal sent by the upper controller.

[0050] 206. Generate a servo motor control signal according to the control command and the feedback signal.

[0051] In some optional embodiments, the feedback signal further includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and step 206 may include:

[0052] 2061. Generate a speed control signal according to the control command and the speed feedback signal.

[0053] 2062. Generate a matrix control signal according to the output current of the servo driver.

[0054] 207. Sending position control signals and servo motor control signals to each servo motor via a plurality of motor power lines.

[0055] The servo control method provided in this embodiment receives control instructions sent by a host controller; receives feedback signals from servo motors, each servo motor is provided with an encoder, and multiple encoders are connected in series through encoder lines, and feedback signals are sent by the encoder lines at the end of the serial line; the host controller generates a position control signal, and sends the servo motor control signal to each servo motor through multiple motor power lines. Multiple encoders are connected in series, which reduces the number of wiring connections between the servo motor and the servo driver, effectively improving the user experience, and the servo driver directly forwards the position feedback signal to the host controller, greatly improving the processing efficiency.

[0056] To implement the above method, the present invention provides a servo drive device. Figure 3 ,include:

[0057] The bus transceiver unit 31 is used to receive control instructions sent by the upper controller and receive feedback signals from the servo motor. Each servo motor is equipped with an encoder. Multiple encoders are connected in series through encoder lines. The feedback signal is sent by the encoder line at the end of the serial line. The servo motor control signal is sent to each servo motor through multiple motor power lines.

[0058] The DSP processor 32 is used to generate a servo motor control signal according to the control instruction and the feedback signal.

[0059] In some optional embodiments, the servo drive device further includes:

[0060] The bus encoder decoding unit 33 is used to decode the feedback signal to obtain a position feedback signal.

[0061] Specifically, the bus encoder decoding unit is used for serial encoder decoding and sending the decoded signal to the DSP unit and the bus transceiver unit.

[0062] The bus transceiver unit 31 is also used to forward the position feedback signal directly to the upper controller so that the upper controller can generate a position control signal according to the control instruction and the position feedback signal, receive the position control signal sent by the upper controller, and send the servo motor control signal and the position control signal to each servo motor through multiple motor power lines.

[0063] Specifically, the bus transceiver unit is used for bus communication processing, receiving input command signals from the external host controller bus, and feeding back servo system status signals.

[0064] In some optional embodiments, the feedback signal further includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and the servo drive device further includes:

[0065] The DSP processor 32 is also used to generate a speed control signal according to the control instruction and the speed feedback signal, and to generate a matrix control signal according to the output current of the servo drive device.

[0066] Correspondingly, in the software control architecture, the position loop performs position control based on the position signal fed back by the encoder. The speed loop calculates the speed based on the signal fed back by the encoder and performs speed control. The current loop detects the output current of the driver, generates a current sampling signal, and performs torque control.

[0067] In some alternative embodiments, see Figure 4 , the above-mentioned servo drive device also includes:

[0068] The plurality of inverter drive units 34 are used to drive and control the inverter units.

[0069] The plurality of inverter units 35 are used to convert the power supply into an AC power supply, and generate an AC voltage and current output to the servo motor according to the driving signal of the inverter drive unit.

[0070] Specifically, the inverter drive unit is used to drive the IGBT (insulated gate bipolar transistor) of the inverter unit to turn on and off, and the inverter unit is used to convert the power of the driver into AC power and generate AC voltage and current output to the motor according to the drive signal of the drive unit.

[0071] The servo drive device provided in this embodiment receives control instructions sent by the upper controller; receives feedback signals from the servo motor, each servo motor is provided with an encoder, and multiple encoders are connected in series through encoder lines, and the feedback signal is sent by the encoder line at the end of the serial line; the upper controller generates a position control signal, and sends the servo motor control signal to each servo motor through multiple motor power lines. Multiple encoders are connected in series, which reduces the number of wiring between the servo motor and the servo drive, effectively improves the user experience, and the servo drive directly forwards the position feedback signal to the upper controller, greatly improving the processing efficiency.

[0072] The embodiment of the present invention also provides a servo drive system, see Figure 5 ,include:

[0073] The upper controller 51 is used to obtain control instructions and send control instructions to the servo driver.

[0074] The servo driver 52 is used to receive control instructions, receive feedback signals from encoders, generate servo motor control signals according to the control instructions and feedback signals, and send the servo motor control signals to each servo motor through a plurality of motor power lines.

[0075] The servo driver is used to control the actions of multiple servo motors, receive input instructions from the upper controller through the bus, and output feedback on the driver status and encoder information.

[0076] A plurality of servo motors 53, each servo motor is provided with an encoder, the plurality of encoders are serially connected via encoder lines, the encoder lines at the ends of the serial lines are connected to the servo drivers, and each encoder sends a feedback signal to each servo driver via the encoder line.

[0077] Servo motors are used to drive various mechanical devices such as industrial robots. Servo motors are equipped with bus encoders, such as Eterncat, Profinet, etc. The encoder lines between servo motors are connected in series, and a single cable is connected to the servo drive.

[0078] In some optional embodiments, after receiving the feedback signal, the servo driver 52 decodes the feedback signal to obtain a position feedback signal, forwards the position feedback signal directly to the host controller, receives the position control signal sent by the host controller, and sends the servo motor control signal and the position control signal to each servo motor through multiple motor power lines.

[0079] Host controller 51, see Figure 6 , including a position loop circuit, the position loop circuit receives a position feedback signal sent by a servo driver, the position loop circuit generates a position control signal according to a control instruction and the position feedback signal, and sends the position control signal to the servo driver.

[0080] In some optional embodiments, the servo drive is also used to receive a position control signal. The servo drive includes a speed loop circuit and a current loop circuit. The speed loop circuit generates a speed control signal according to a control instruction and a speed feedback signal. The current loop circuit detects the output current of the servo drive. The current loop circuit generates a matrix control signal according to the output current.

[0081] Specifically, the DSP processor in the driver is used for core processing of the servo motor control algorithm, calculates the pulse width modulation signal of the motor current according to the operation instruction, and outputs it to the drive unit.

[0082] The embodiment of the present invention is mainly used in the servo system for industrial robots, in which the encoder of the servo motor can adopt an industrial bus interface such as Ethercat, Profinet and other high-speed industrial buses. The encoder of the servo motor is serially connected to the servo driver through the bus interface. In this system, the servo driver can drive the architecture of multiple servo motors at the same time, and directly send the encoder information to the host controller, so that the host controller can receive the encoder data in real time, reduce the calculation and processing of the driver DSP chip, and the host controller can call data more conveniently and flexibly. In terms of software control architecture, the servo system integrates the position loop into the architecture of the host control system, and the host controller can collect the encoder position information in real time, which greatly improves the control precision and calculation accuracy. The servo driver focuses on executing the speed loop and the current loop, which is more efficient.

[0083] The working process of the above private service system: After the servo drive is powered on, the drive DSP processor is initialized, and the position of each servo motor is read and the speed information is calculated through the bus encoder decoding unit (Ethernet uses optical fiber as the transmission medium, the wiring harness is simple, and the anti-interference ability is stronger and the transmission distance is longer. Some Ethernets such as EtherCAT are based on the standard Ethernet physical layer, so that the real-time characteristics of controlling multiple axes can be less than 100us, and the synchronization accuracy can be less than 10ns). At the same time, the system determines whether there is a communication abnormality, and waits for the upper control instruction if there is no abnormality. At the same time, the bus transceiver unit uploads the position information of each servo motor to the upper controller through the bus. When the servo drive receives the operation instruction from the upper controller, the DSP processor outputs a signal to the inverter drive unit, and the inverter unit converts the power of the drive into AC power, and generates AC voltage and current output to the servo motor according to the drive signal of the drive unit. The servo motor then runs, and the real-time position information of the encoder is transmitted to the servo drive DSP processor through the bus encoder decoding unit, and uploaded to the upper controller at the same time.

[0084] Software control process: After the system detects no abnormalities, the upper controller directly reads the position information of each axis through the bus, compares it with the upper internal position planning position, performs position control, outputs the target speed command to the servo drive speed loop, calculates the speed based on the encoder feedback signal, and performs the speed control loop. Then outputs the current command to the current loop, generates the current sampling signal by detecting the output current of the drive, performs torque control, generates the motor control control signal, and drives the motors of each axis to rotate.

[0085] The servo drive system provided in this embodiment receives control instructions sent by the upper controller; receives feedback signals from the servo motor, each servo motor is provided with an encoder, and multiple encoders are serially connected through encoder lines, and the feedback signal is sent by the encoder line at the end of the serial line; the upper controller includes a position loop circuit, which generates a position control signal, and sends the servo motor control signal to each servo motor through multiple motor power lines. Multiple encoders are connected in series, which reduces the number of wiring between the servo motor and the servo driver, effectively improving the user experience, and the servo driver directly forwards the position feedback signal to the upper controller, greatly improving the processing efficiency.

[0086] Based on the same inventive concept, Figure 7 As shown, the present application also provides a servo driver, comprising:

[0087] at least one processor 71 and at least one memory 72;

[0088] The memory stores executable instructions for the processor;

[0089] The processor is configured to execute the servo control method provided by the above embodiment.

[0090] The identity recognition system provided by the embodiment of the present application stores executable instructions of the processor through a memory, and when the executable instructions are executed, the processor can.

[0091] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0092] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

Claims

1. A servo control method, characterized in that: The method is implemented by a servo drive, and the method comprises: Receive control instructions sent by the upper controller; Receiving feedback signals from servo motors, each servo motor is provided with an encoder, and multiple encoders are serially connected through encoder lines, and the feedback signals are sent by the encoder lines at the end of the serial connection; Generate a servo motor control signal according to the control instruction and the feedback signal; The servo motor control signal is sent to each servo motor through a plurality of motor power lines.

2. The method according to claim 1, characterized in that: Before generating the servo motor control signal according to the control instruction and the feedback signal, the method further includes: Decoding the feedback signal to obtain a position feedback signal; forwarding the position feedback signal directly to the upper controller, so that the upper controller generates a position control signal according to the control instruction and the position feedback signal; Receiving the position control signal sent by the upper controller; Sending the servo motor control signal to each servo motor through a plurality of motor power lines includes: sending the servo motor control signal and the position control signal to each servo motor through a plurality of motor power lines.

3. The method according to claim 2, characterized in that: The feedback signal further includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and generating the servo motor control signal according to the control instruction and the feedback signal includes: generating the speed control signal according to the control instruction and the speed feedback signal; The matrix control signal is generated according to the output current of the servo driver.

4. A servo drive device, characterized in that: include: A bus transceiver unit is used to receive control instructions sent by the upper controller and receive feedback signals from the servo motors. Each servo motor is provided with an encoder. Multiple encoders are serially connected through encoder lines. The feedback signal is sent by the encoder line at the end of the serial connection. The servo motor control signal is sent to each servo motor through multiple motor power lines. The DSP processor is used to generate a servo motor control signal according to the control instruction and the feedback signal.

5. The servo drive device according to claim 4, characterized in that: Also includes: A bus encoder decoding unit, used for decoding the feedback signal to obtain a position feedback signal; The bus transceiver unit is also used to forward the position feedback signal directly to the host controller, so that the host controller can generate a position control signal according to the control instruction and the position feedback signal, receive the position control signal sent by the host controller, and send the servo motor control signal and the position control signal to each servo motor through multiple motor power lines.

6. The servo drive device according to claim 5, characterized in that: The feedback signal further includes a speed feedback signal, the servo motor control signal includes a speed control signal and a matrix control signal, and the servo driver further includes: The DSP processor is further used to generate the speed control signal according to the control instruction and the speed feedback signal, and to generate the matrix control signal according to the output current of the servo driver.

7. The servo drive device according to claim 6, characterized in that: Also includes: A plurality of inverter drive units, used for driving and controlling the inverter units; Multiple inverter units are used to convert power into AC power and generate AC voltage and current output to the servo motor according to the drive signal of the inverter drive unit.

8. A servo drive system, characterized in that: include: The upper controller is used to obtain control instructions and send the control instructions to the servo driver; A servo driver, configured to receive the control instruction, receive a feedback signal from an encoder, generate a servo motor control signal according to the control instruction and the feedback signal, and send the servo motor control signal to each servo motor through a plurality of motor power lines; A plurality of servo motors, each servo motor is provided with an encoder, the plurality of encoders are connected in series through encoder lines, the encoder lines at the ends of the series are connected to the servo driver, and each encoder sends the feedback signal to each servo driver through the encoder line.

9. The system according to claim 8, characterized in that: After receiving the feedback signal, the servo driver decodes the feedback signal to obtain a position feedback signal, directly forwards the position feedback signal to the host controller, receives the position control signal sent by the host controller, and sends the servo motor control signal and the position control signal to each servo motor through a plurality of motor power lines; The upper controller includes a position loop circuit, which receives the position feedback signal sent by the servo driver, generates a position control signal according to the control instruction and the position feedback signal, and sends the position control signal to the servo driver.

10. The system according to claim 9, characterized in that: The servo driver is also used to receive the position control signal. The servo driver includes a speed loop circuit and a current loop circuit. The speed loop circuit generates a speed control signal according to the control instruction and the speed feedback signal. The current loop circuit detects the output current of the servo driver. The current loop circuit generates a matrix control signal according to the output current.

11. A servo driver, comprising: at least one processor and at least one memory; The memory stores executable instructions of the processor; The processor is configured to execute the servo control method described in any one of 1-3 above.

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